[Arran]

That hot plate/double boiler thing is called a glue pot, you still see them around from time to time at garage sales and flea markets, needless to say there is not a large market for them anymore. Hide glue does have some advantages but is has many more disadvantages. Ever wonder why old chairs have every joint loose? Answer, hide glue. Ever wonder why drawers fall apart in an old dresser? Hide glue. Ever wonder why the veneer is lifting off a radio cabinet? Hide glue.
I knew a fellow who tried some hide glue, he saw it on a PBS documentary about radio collectors. The guys on there swore by the stuff, and the kind they were using was pre mixed in a bottle much like the yellow glue. He tried gluing something structural together with it, let it cure long and hard, took the clamps off, a day later, "Sproing", popped apart again. There could be a number of reasons for this but he went back and reglued it with carpenters yellow glue and it stayed put.
Hide glue has virtually no resistance to moisture. It also has a habit of crystallizing on it's own, turning to dust, and just falling apart. Maybe it's fine for veneer if used the right way but I would not trust it to hold a cabinet leg in place.
Regards
Arran