The best tip I got about the "not fun" problem is to do it while you're at your PC surfing the web or going through email. When I do this, the 20 minutes seems to go in a second.
Personally the thing that keeps me coming back is how well I feel afterwards. There's just this certain lightness (especially in my chest) that I only feel after a good OP. Does good things for my mood too. Try it with virgin coconut oil to really notice some benefits.