Understanding Certain pills.?

I don't understand. What i'm trying to say is that i want pills to make my penis larger on for a certain amount of time, not permanently. I do want it to be permanently but i would be taking pills every day and it would be a waste of money for me. I keep researching that pills don't make em bigger but i want it bigger ONLY FOR SEX NOT PERMANENTLY. Like increase my size an inch or 2 everytime i take a pill for sex. Does that work? Thanks