If you go to Rid-X site under FAQ they don't recommend it for RV use. Some say that the micro organisms that dissolve the solid wastes also will dissolve the rubber seals over continued use. I never used anything but water and at the end of the year dish washing detergent and a 3/4 full tank and a long ride home, then dump before storing for the winter. If you are concerned about a build up you can open the toilet valve after final dumping and turn on the fantastic fan with all windows closed and if no odor is detected your tank is clean.