I think the idea is that it stains the wet toilet paper and absorbs it smoke, kinda the same was as putting a piece of toilet paper over a bong and smoking it leaves the piece of toilet paper covered in resin. Id say ithe contraption would stink a bit though.
I just feel like it would be hard to blow through wet toilet paper, the stuff absorbs water so easily but I guess I haven’t tried it either. Maybe a very light wetting of the toilet paper so it’s not a giant spitball.
-GC