Hmmmm....Interesting discussion, on whether or not RidX or other chemicals actually break anything down or not. I have no idea if they do or not. Have to agree, though, that you don't keep the 'stuff' in your RV holding tank long enough for much if any decomposition to occur, regardless.
That said, I *do* use chemicals, for the simple fact that it minimizes the odor. That alone makes it worth it for me.
I've been RV camping for over 20 years now. I've learned that when you dump your tanks (especially the black tank), its very easy for some 'odor' to get out, no matter how careful you are or how well-maintained your equipment is. Also know that campground RV sites frequently put you in close proximity to your neighbors. Said neighbors and those nearby at a dump station, will very much appreciate you using some kind of chemicals (or dish soap, whatever) to reduce the smell some.