Charmin Toilet paper is safe for use in RV's and I use Charmin Toilet paper myself all the time when I go camping in my RV and it works just fine.
Never had a problem with the Charmin Toilet Paper clogging my RV tank as it breaks down just fine with the use of RV toilet chemicals.
Just be sure to empty your RV waste water tanks when they get near full to avoid the toilet of the RV backing up.
But as long as you empty the RV toilet often enough you should have no problems using Charmin Toilet Paper or any other toilet paper in your RV toilet.
RV toilet paper that is made for RV toilets is just designed to break down faster in the RV toilet tank than other toilet paper.
But use of regular toilet paper in an RV toilet is just fine.
Just don't put too much toilet paper in your RV toilet at a time to avoid it clogging up and you'll be just fine.