Toilet paper

We use Scott's in the house and in the camper.

I use White Cloud soft from Walmart. It totally breaks down, but is not the expensive sandpaper of the so-called RV toilet paper. To test a toilet paper for rv suitability, put 3 sheets or so in a small bowl (like a cereal bowl), count to 5, then stir with your finger. It should immediately break up. It's amazing to see. Try it with any so called "strong" paper, and you will see how your valve can get clogged. Good news about R-POD is that you can reach the valve to clean it. My Airstream valve could not be reached when it got clogged with Canadian toilet paper. Big labor charge to replace valve.

It is fairly common to put ice cubes down in the black water tank and ride around to clear stuff of the walls and keep it from building up.

If you know the black tank is nice and clean, no need to keep any water in it.  If you aren't too sure... a couple or three gallons of water in the tank as you're going down the road will slosh the walls of the tank and prevent bits of toilet paper and other things from drying into a hard crust that can be nearly impossible to remove.  Too much of that and you can have clogs and other potential issues.  I like to fill my black tank with clean water sometimes when I'm home; let it sit for a day or two, drain it and repeat.

TT

We used Scotts single ply TP for quite a while and didn't have any problems.  I really don't think it makes too much difference.  Just make sure you use plenty of water when flushing and keep water in the black tank at all times.  Add several flushes to the tank after dumping everything at the dump station.  It's easiest if you keep some water in your fresh water tank for this purpose and while using the toilet at rest areas, etc.