Ways not to lock your bike

The same size as the allen keys you use on them, i.e. probably some combination of 4 / 5 / 6mm depending on your exact stem / clamp / seatpost.

I have one superglued into my Nitto Pearl stem bolt but I also tried gluing one in the seat binder bolt and that bounced out from road vibration. I have Atomic 22 bolts in there and the saddle clamp now. Nice but pricey.

ah, common sense. I assumed maybe a smaller BB would make it slightly easier to apply acetone, in case I need to remove afterwards.,.