<<A torch such as you descibe IS the ideal solution to this rusty
problem - however, many of us do not have easy access to such a tool.
So, what slightly "lower-tech" solutions might work?>>

Easy access would be quite simple.

Buy.
Rent.
Borrow.
Beg.
Pay someone to do the job or steal a torch
I made it simple.

I went just went out out and bought mine.

Paid for itself many time's.