Cleaning processor

In the process of cleaning thermal paste off of my processor some of the cleaning solution got on the pin side. How long should I wait before putting it in my motherboard? I'm using the cleaner from ArcticSilver.

Depends on what's in it.  If it's just iso, let it dry and you're good to go.  If not, you should probably clean it of.  Once again, isopropanol is your friend.