We just don't feel comfortable spraying mysterious combinations of chemicals just to keep our shower clean. And, if you think about it, buying something that's mostly water and which is intended to go directly down the drain just doesn't make sense. Instead, we've adopted a slightly more labor-intensive technology that seems to work just as well: squeegee! Plus, it's a lot more fun to say.
The key is to find one that's flexible enough to conform to the surfaces in your shower. Read on for our favorite and a few alternatives.

• The California Water Blade works the best of anything we've tried. It's marketed as a way to get water off of cars, but don't let that stop you from using it in the shower. The blade is soft and flexible, which helps it to get nearly all the water off even irregular tile. But it has a flaw: no handle. It's not difficult to use, but storage is a problem. You can't hang it, so it has to stand on end with the shampoo. Ours always falls over. Widely available in local stores; $18 at Amazon.

• For those with more traditional tastes in squeegees, check out Oxo's Good Grips Squeegees. We're not sold on the utility of a $12 stainless steel squeegee (wouldn't it be permanently spotted?), but the plastic model has the same good ergonomics. We've used it and it gets most of the water off surfaces (though it's no Water Blade.) At $6, it's a deal.

• This most modernist of squeegees can be yours for about $14. While we like its minimal lines and tool-like demeanor, we're concerned about the functionality of the very narrow blade, and the product reviews seem to confirm our suspicions. We haven't tested it ourselves, though, so we'll keep an open mind.

Sheex Bedding
A squeegee will not clean your grout. That's part of why there's bleach in a typical shower cleaner.
The "mysterious" surfactant is just something acidic, like lemon or vinegar, which you also shouldn't get on marble or brass. The surfactant also dissolves certain types of deposits. (If you have hard water, a squeegee is not a solution, and your water softener will contain "chemicals.")
The reason that the cleaner is mostly water is that these substances are mild enough to use when in a mostly water solution -- it's not some weird rip-off where you're not getting real product.
I'm not a huge fan of special-purpose cleaners, but there are good reasons to use some kind of cleaner to dissolve deposits, both mineral and fatty.
My friend said that the army makes that coat the shower tiles with baby oil so it repels water and you don't end up with mildew. I keep meaning to try that. My mom used to do the squeegee thing and it seemed to work fairly well.
My son is very sensitive to chemicals so I've been using all sorts of cleaning alternatives around our house. Some have worked quite well and some have not. The squeegee has been a very good product in our shower. Because mold grows on wet surfaces, if you wipe the whole thing down after each shower there really is no reason to use bleach to get rid of mildew/mold. If you feel that simply wiping it down isn't good enough you can always use a mild baking soda/water mix to scrub out the grout. But, since we are talking about green living, why use more products when all you really need to do is get rid of the mold maker. . .water.
We've got a glass shower door and that first purple squeegee works fine (something like $10 at Kragen Auto Parts). Also coated the door with Rain-ex, made for car windshields to keep the water beading up. But these are all solutions for your glass, not your tile.
I tried cleaning our grout with vinegar and baking soda and it worked wonders. It's not as easy as a spray, but i was shocked at how white my grout was, almost immediately.
I use Method's shower spray, but not on my shower.... I have one just-potty-trained kid and one who's just starting to get interested. I use the spray to pre-coat the little potty and the areas most susceptible to my son's... misguided, shall we say?... aims. I find that it makes it so much easier to clean up the "spills" and works wonders for leaving the bathroom smelling acceptable. There are refill bottles available but alas they don't sell it as a concentrate. There are also diy recipes out there such as this one:
DIY Daily Shower Cleaner
These measurements are approximate.
1/4 cup rubbing alcohol
10-15 drops tea tree s=essential oil (tea tree is anti-fungal | good for mold) – Thyme can also be used.
1/4 cup white vinegar
Filtered Water
In a large spray bottle (about750ml), combine alcohol and tea tree and mix, then add vinegar and water and mix again. Label the bottle for people to shake it before use as sometimes the oil floats on top. To avoid this issue, you can use Polysorbate 20 (try www.voyageursoapandcandle.com) which helps keep the ingredients mixed.
http://thefrugalvegan.wordpress.com/2009/05/29/diy-daily-shower-cleaner/
(Disclaimer: I haven't actually tried the above recipe but it certainly gets around the whole transporting-a-product-whose-main-ingredient-is-water thing.)