I am Hoke, and I never got past basic Chemistry, so I'll never be confused with Mark Lipton.
Sam, I know relatively little about port tongs, except that I owned a pair for a while, and another friend owned a pair as well. Friend and I, one cold winter night suited for old port, stoked up the fireplace to a considerable roar, created some lovely banked embers, and put his port tongs in the fireplace.
We first tried the port tongs on some younger bottles, to discover that port tongs are not easy to use and one must practice before tackling the old bottles lest you screw it up. (I think that's called the scientific method.) Because we screwed said younger bottle---then progressively screwed up several empty bottles trying to get the technique right.
Finally, we did develop some slight proficiency. And once developed, that proficiency was never used again.
Seriously, it was fun to do, and if one had a good supply of very old portos, it might conceivably come in handy. The tricky part is getting the tongs heated to a high enough point, applying them quickly, leaving them in place long enough to create the fracture zone where desired, and then 'chinking off' the top delicately. I'd practice first.
Question for Mark "I am not Hoke" Lipton: Chemistry Man, we discovered that newer bottles were very much more difficult to tong and break off cleanly than some older bottles we worked on. Would that possibly be because newer glass/bottles are stronger and more resistant to fracturing, even when heat is applied?