Does dirt tend to build up quickly after using this method?

Not really, which is why we had to let it go a full month without cleaning to really get visible grime that would photograph. We wipe things down once a week and don't seem to have a problem.

Any special reason for using a grapefruit? (What about a lemon?) And is it ok to use ordinary Morton's salt?

Baking soda, a squirt of liquid soap and a wet microfiber cloth or rag. Rub tub, then shower wall, then tub. Rinse with vinegar to make your bathtub sparkle like new.

Our washing machine drains into the bathtub. Your month long ring looks like ours after a single day! Grapefruit wouldn't cut it. Neither did lemon. Something about the mix of baking soda's abrasiveness and the dish soaps grease cutting power works like a charm with no hard scrubbing...just a quick rub and rinse! I've tried every trick on the internet and the above baking soda method is the only one that makes it look clean again!

I'd rather eat the grapefruit!

I was thinking the same thing, rather eat the grapefruit. Unless I had a tree, then I'd have extra.

This seems like a waste of a perfectly good grapefruit. I'd probably use it to clean after juicing it or enjoying it for breakfast.

Oh, please!! I'm NOT going to waste a perfectly good grapefruit when I can use something else. This is ABSURD!

the BEST green cleaning straight outta the pantry is 2 Tablespoons on baking soda mixed with a 1/4 cup plant based dishwashing liquid. Mix together until it looks like frosting. spread on tub and shower with old sponge. It makes all the silver parts of the tub so shiny and ELIMINATES the scum in the tub! Plus it smells great!

my favorite plant based dishwashing liquid is ecover!

I tried this with the peel of a lemon and some Morton's salt after making juice. It's a good way to use the peel instead of just throw it away...

Useful tip for those with an abundantly-producing grapefruit tree. Ridiculous for everyone else. What a waste of food and money.

I have an abundantly producing grapefruit tree that has THE MOST sour grapefruit on earth. I usually give the fruit to a neighbor who loves his Salty Dogs. Apparently after the first, you don't really care how tart the juice maybe. He may be going on the wagon so I can have a clean wonderful smelling bath. Thank you.

Isn't anybody concerned about the abrasiveness of the salt? I'm not taking salt anywhere near my tub.

mmmmm... salty dogs.... thanks @GinaBlue
anyway, I think I will try next time I juice a grapefruit, then I will save the remaining pulpy rind for cleaning the tub. Then it's like recycling, and not a misuse of a food commodity.

Its simple. Make juice, clean your bath. No packaging to recycle afterwards just put the skin on the compost. Much better to use less plastic/cardboard containers that will use energy when being recycled. No unnecessary waste of food or other...

I read on AP about using dishwashing liquid to clean the tub and it really works like a charm. A lot better than the stuff with bleach, and less toxic smelling.

This cleaning method would be pricey for me, as grapefruits are not that cheap around here. Plus I don't think one grapefruit would even cut it.

Would coarse salt scratch my acrylic tub?

You should be fine with the Kosher, but to stay on the safe side, you can always use table salt instead, it will have as much cleaning power without the worry of scratching.

I can't believe all the people saying it's a waste of a grape fruit! It's better to produce something in a factory, wasting all that energy and causing pollution, than to pick up an extra grapefruit? Do you know how much produce ends up getting thrown out at grocery stores? I think it's great to utilize a renewable resource instead of having to create a whole new product!

Thanks for the tip!

I have two grapefruit trees that NEVER stop producing! Did this trick today and it worked beautifully, and oh wow did it smell amazing! Thanks for the tip

Gently juice the grapefruit and then just use the rind. Most of the bitter in grapefruit comes from the skin and the rind, so you can kill two birds with one stone - make delicious juice and, instead of squeezing out every last bitter bit, use the remaining juice along with some salt as a powerful cleanser.

I've used this same method,with a lemon, to scrub my plastic cutting boards. It cleans them and takes care of any garlic/onion odors in no time flat. Then, the leftover rinds get tossed in the food disposer and ground up, thus deodorizing it as well.

worked like shite on my tub. in fact- it scratched it up more. would not recommend for people living in cheap apartments.

It worked great on the white cakey stuff on my lousy old apartment bathtub, except it clogged my tub and I had to have a plumber come out, I tried to unclog it myself with a plunger but no luck. Next time, I'll close the tub stopper before working, as the white cakey stuff on the tub fell off in chunks - that was what clogged the drain. But the room smelled fantastic! My parents have a grapefruit tree, fortunately.

Perfect for grapefruits past their prime!

OK, this makes the bathroom smell great, but does NOT work on fiberglass tubs. :/

okay, it isn't absurd if you can't or do want to use chemical cleaners, and depending on where you live, like a southern state, citrus fruits are an inexpensive alternative, and who says you can't use it on other parts of the house, like kitchen sinks and counters. who wouldn't want a citrusy-fresh smelling home?

We have two grapefruit trees (yellow ones, not red ones) and neither one of us like this type of grapefruit. This would be a great use for them, rather than let them rot in the sun!

I'm with Stone Maison -- that salt is abrasive. There's a reason that tub manufacturers have been telling us for years not to use abrasive cleaners (unless you have a good old-fashioned enamel tub, which few of us do). They create little grooves that will hold the next load of dirt better. Thinking up a clever combination nontraditional ingredients doesn't make it any better.

Can't wait to try this, sarahrae! I have two that are on their last leg.

Two things: applying the same premise (periodically) using a halved lemon and TABLE salt, you can shine copper bottom pans.
Also, the leftover peels from grapefruits/lemons/ or oranges can be stored (the longer the better) in jars with covered in Olive Oil. Makes a fantastic furniture oil/polish. Smells wonderful too.