"Within 48 hours, the septic tank starter, (which is non-caustic and promotes natural bacterial growth) will have begun its work and you can add more dog doo. You can then begin to add it daily. This waste biodegrades and flows into the subsoil."The retail version of the idea above is the Doggie Dooley, described as a "miniature septic tank, utilizing enzyme and bacteria action to automatically reduce dog waste to a ground absorbing liquid." Works with 1-4 dogs and retails for $89.95. A more affordable PetSafe Eco Clean InGround Waste Digester PLUS is available for about $20 less.
And then there is NatureMill's compact version which is meant for outdoor use and can be used with scraps, cage shavings, and pet waste. The composter is priced at $399 and can handle the waste of 2 large dogs, or 4 cats, rabbits, hamsters, snakes, ferrets, or other small animals . We're not exactly sure why this model is priced so expensive, but some of the cost might be due to the above ground design.