The trick with a strat is when you see greenish blue slime running out from around the trem or pickguard it's time. i used to remove the guard once a year just cause there would be a heavy line of gunk under there. I hadn't pulled that bigsby since I got the guitar in '21, so three summers of hot outdoor gigs. It looked like someone had traced the trem and filled it in with shit and corruption and the backside had a good bit of pitting in the gold plate. Good thing the guitar is urethane finish, the crust wiped off with a little elbow grease.