I have seen the video where the producer claimed no benefit from ice cubes. The test rig and the testing was much different than real life operation. While he did provide much usable information, the idea that ice cubes are worthless is something that I don' t agree with. While it may not do great things, I'm sure that there is some benefit.
The idea of not using chemicals to reduce odor, because you don't smell it in your rig, perhaps others don't appreciate the stink when you dump. In a crowded campground we have to be respectful of others.
