Specially made RV toilet paper is designed to break down faster inside an RV sewage holding tank so that it doesn't clog the tank coming out.
You don't have to use special RV toilet paper if you don't want too and can use toilet paper that is made as septic safe which most if not all toilet paper you buy in the store is.
As long as you use RV toilet chemicals in the RV toilet tank and empty it often and don't use a whole lot of the regular toilet paper it should not be a problem to use regular household toilet paper in your RV.