We don't shave hits. You do not get credit for ins unless your ins produce an out. This is pretty common on top lists. We have just recently implemented new C++/MySql scripts that track all incomming hits by site and IP, then if that IP clicks out from ANY picka site you will be credited with the proper in and out hit.
Basically, the new scripts reward people for productive traffic, and practically eliminate all of the cheaters.
Why would we shave ins on a top list anyway? What would the purpose be?