Question: Do you really have to buy RV toilet paper, or is a brand such as Scott’s okay to use?
Answer: There may be different opinions on this subject, but we can tell you what we do ourselves. And there is a test you can use to assess solubility of different brands.
We use Scott’s 1000 sheet toilet paper. It is a 1-ply paper that we have found dissolves easily. We have been using it for years and not had a problem.
You may be able to use a 2-ply sheet if you find something that dissolves easily. We haven’t pursued this because we are fine with what we have been usuing.
The important thing is to find a product that is readily water soluble. To test this out, fill an empty jar (like a quart mayo jar) about half full of water. Put in a sheet or two of your toilet paper. Shake the jar rapidly for a few seconds. If the toilet paper falls apart, it is a good choice for your RV holding tank.