imho, it wont destroy your pickup.
Pickup are meant to pick up signal and get amplified to be heard. Strings vibration to pickup to amplifer to user hearing, in most simplified explanation.
Some rockstar shout into their pickup during intense moment and get amplifed
some rockstar use remote control on pickup for "chiu chiu chiu" sound
Some rockstar use toy gun sound aim towards the pickup for extra effect
Some locale basserer/guitarer put handphone onto pickup while playing obsence moaning sound, taxi driver complaining about politician, auto shaver motor running while in jamming session, gig time etc
To destroy pickup, over a long period of time, use a hammer everyday to continous hitting again the pickup, heat the pickup or any other way to demagnetize it.