Makeshift slide hammer bead breaker worked super well on a stubborn bead!
The threads of the allthread did mar my rim a bit though, most people would want to put a smaller pipe around the lower section to cover the threads. I on the other hand do not really care because this particular rim has been bent and unbent several times. It is FUBAR and I took the tire off this time to clean out the sealing goo that did not work, before installing an inner tube.
I am not replacing the rim because the tire is also mostly demolished and this stuff is pretty spendy.