The knowledgeable RV people had me spending money on RV tank treatments, then I figured out they were not so knowledgeable. Tank smell inside the RV? The system is leaking and a plumbing smoke test will find the leak. NO chemicals for me. If you have money in your wallet Camping World and WalMart have a product to remove it.
I added Zerk fittings to the holding tank valves and give them a bit of grease every now and then. I really do not care that petroleum may or may not be good for the seals, they are not going to last forever and I do not want to deal with stuck valves. I had my last RV 10 years full timing and the grease did not destroy the seals.
