a few years back I had creak - out of the saddle uphill - narrowed it to the BB - campy Chorus - my LBS recommended Loctite 660 , an epoxy resin - put some on each side of the bearing, slide the cups on, let it cure overnight & next day no creaks - the 660 addresses the slippage between the bearing & cups under load.

this remedy worked for the Campy BB design - wouldn't apply to Shimano outboard bearing or the newer Campy ultra torque designs .