I consider it a waste of good oil
And a contributor to holding tank odor. Equipment mfrs are slow to figure out sometimes that their equipment is only one part of a complete system...so they recommend something that works for them, but causes more problems than it solves in the rest of the system. Anything that can be poured down a toilet is so thin that it just washes out in a few flushes, but it ends up in the holding tank where it puts an oil slick on surface of the contents, effectively sealing it...creating the anaerobic environment necessary to have a stinking holding tank.Otoh, a few drops of oil at a time prob'ly won't hurt...it's just a never-ending battle, every couple of weeks.Every marine toilet leaves the factory slathered in teflon grease...it lasts at least a season. So you decide how much effort you want to put into maintaining your toilet--a never-ending battle with oil...or replace the teflon grease once a years, which is all of a 15 minutes job.