Those bullies are so powerful that killing it quickly would really be the only foolproof solution. Not sure how you would get there. Long knife maybe? Plenty of videos about that show them taking multiple bullets with little to no effect.
@Mountain Bug
Back in the days of 'black and white', and long before Bullies were 'banned' in the UK...
Long short.
Our team executed a search warrant.
The homeowner's (ironic - it was not a home and the shite did not own it) Bully, latched onto one of the lads' inner thigh.
Fortunately (not always the case in the UK), some of the team were armed, and they emptied a magazine (very carefully - or as carefully as you can when the damn thing is latched on to a colleague) into it. The dog died. They can be killed.
However, the dead dog's jaws still had to be prised off, (broken) my colleague's thigh.
He was left with a scar that would impress a pirate...
My colleague survived this unhappy incident but was never again 'first through the door"...
If you are not armed (in extremis) a finger up the anus (the dog's), can cause the dog enough surprise/pain/pleasure (I made that one up), to give cause for it to be distracted from it's assault.