Uhh, take it from the son of a toilet paper roll maker... Stop using it, immediatly (at least in your engine).
Modern toilet paper has lots of dies bleaches, glues, and other chemicals added to it so the cheapest pulp can be used to make it. These chemicals are not necessarily good for your engine and may react with the additives in your oil. The fibers also tend to come apart when wet. You are probably doing more harm than good using a roll of TP. Get a real filter, it will work a lot better and there is no risk. While it may have been ok to do this in 1955, since TP was a lot less soft and had less chemicals and better pulp it is not a good idea now.
If you really feel like you have to use TP use the single ply Scott Tissue 1000 sheet roll, it is the best quality paper with the least amount of die and glue.
