The act of getting rid of a friend (be they virtual or actual) by deleting him/her from your life. This is usually achieved by removing said friend from either your virtual life (MySpace, Facebook, LiveJournal, etc.) or your actual life (Don't return calls or texts, ignore/delay emails, etc.) Basically a Friends Cleanse means 'eh, I don't want to deal with you anymore'.
Damn. I had like close to 130 people on my MySpace... but I had to do a Friends Cleanse. Too many people were posting bulletins and shit I wasn't even interested in.
Dude... I'm getting way too many calls/texts from XXX. Time for a mobile phone Friends Cleanse.