I've never had a problem with WinClean brass pockets. Others have caused problems occasionally. After a reloading session, I put everything through a case gauge. The ones that fail that test (and the really ugly problems like crumpled brass, shaved bullets, etc.), I check the headstamps of and if a repeat offender shows up, I toss that brass. Usually, if its a brass issue, all of that headstamp in that run will cause you grief...
My $0.02