You can pick your nose.
You can also pick your friends.
But you can't wipe your friends on the back of the couch.

It's funny you mention mailing boogers. When I get junk mail with a return envelope -- postage paid -- that's exactly what I do. Sometimes I also mail them perverted poetry if I have time.

Good luck to you sir.
Nice to know I'm not alone.
Great minds think alike.