Anal?

this is gonna be TMI but the title says it anyway.

I've never done anal. My boyfriend of 1.5 years has never done anal but he wants to try. I kinda wanna try too but twice we've tried and it REALLY hurt, tho it barely made it in. I know we have to use toys and lube and fingers, but I don't think I'll be able to relax unless I know it's clean inside.

How can I be sure it's clean inside my asshole? Or how do I clean it?

Please give me legit answers I don't actually know 😬