groupy,
I can't give you a specific answer to your question, but what I've read here on this forum about another brand of tips (Triangle I believe), it was said to drop them into a glass of water. The ones that sink are the good ones. The LePro tips, being a hard tip to begin with, I would soak in water for a few hours and press them in a vise until dry before installing one anyway. I hope this helps.
Maniac