Over 20 years working with my travel trailer and fifth wheel holding tanks, looking for new ways to keep them clean. I've tried all sorts of methods which work well, at least for me.
There is back flushing, rinsing with the black tank flusher, using the toilet wand down the toilet hole, I even used a power washer a couple times in the black tank through the toilet hole, running water down the toilet itself, driving on the road and letting the tanks slosh, various chemical treatments, and the list could probably go on and on.
For me, back flushing works very well, and I'll continue doing that. But that does not help the grey tanks very much.
RV sewer treatments help some, and I've used septic tank Rid-x a few times too.
But in time, that kitchen sink tank really begins to stink when dumping. I dump on the ground at home usually, and run the black tank into my septic tank at home. I've noticed the last year, how smelly the kitchen sink tank is. No smells inside the camper, only when I dump it at home on the ground. I used a bit of bleach and that works for a time or two, but when dumping, the food particles still drip out of those last few moments. So, I know there are food particles trapped inside that tank.
In my house, I use the stuff in the photo below. As I said, we are on a septic tank and this stuff does great, not only for keeping pipes flowing in the house, but also puts those emzynes in the septic tank.
A few days ago, I took the time actually read the label and "it" jumped out at me like "SURPRISE" at a birth day party! It's good for RV's too!
So, I tried it at home. Although we are now using the camper again full time in the drive way, I poured some down each tank and then used the camper as we normally would. The tanks sat while in use, for about 5 day, and when I dumped them ... OH MY GOODNESS! The stuff that came out of the kitchen sink drain was hideous! But ... it did not smell!
The bathroom grey tank was incredible what came out of it too, and the black tank ... well ... I'll leave that one to your imagination.
Mind you, I am adamant about cleaning my tanks when dumping. I do the back flush, keep Dawn and Laundry Soap in the black tank (and backflushing with the grey tank using a washing machine .... well .... that's LOTS of laundry soap washing it out). But, when those enzymes started eating away at the residue stuck on the sides, it made me realize just how inefficient "dumping with plenty of water" really is.
I purchase this stuff at Lowe's Home Improvement. It calls for 1 ounce down each drain. That's what I used. I now have a new "tool" for tank maintenance. I'm going to continue to add that 1 ounce down each drain every time I dump now.
This stuff does work and it does work really, really nice in the RV.
