Expensive loo paper, is it necessary?

Ional

As returners to caravanning, impressed that we no longer have a porta potti, but an up market electric flush/cassette job! However do we really need to buy Thetford loo paper for it? It seems very expensive, and what do people do whilst abroad. Surely I
don t need to stock up with it!  Do any of you use cheap supermarket rolls?