Hello, from someone who needs toilet slavery, the reason I do it is that because it is very humiliating, probably the must debasing thing that a sub can do. I crave the feeling of being totally de-humanised and used as an object. I don't enjoy it when mistresses try to sex it up, I enjoy total distain. I don't particularly enjoy the taste during but that is part of it. Also, the after taste lasts most of the day, not pleasant, but well worth it, you have to go back for more. I am still trying to find the right mistress form me, that that force feeds, preferraby with a funnel! I hope this helps.