Which threadlock on bottle cage bolts?
Loctite 243 seems like the best bet, but 222 could work.
From https://www.henkel-adhesives.com:

LOCTITE® 243 is a general purpose threadlocker of medium bond strength. This threadlocker secures and seal bolts, nuts and studs to prevent loosening due to vibration.
LOCTITE® 222 is a low-strength threadlocker that allows the adjustment of screws including countersunk head screws and set screws. Good on low-strength metals which could fracture during disassembly