I was just watch an online streaming of a repairwoman pour hotwater onto the residue glue and put a towel around the butt, then wait half a minute before wiping the water away
That's weird, but if it works and she's comfortable doing it, then ok. I can think of a few reasons not to use that method, but since I haven't actually tried it I won't knock it. I do a lot of strange things that other makers think is crazy or bad, but it works & it's my name on the work so it's my burden to bare if something goes wrong.
My point is that there are a 100 ways to skin a cat. What matters is the end result. If she uses hot water to loosen the glue, and it works, who am I to say she's wrong? So long as her customer is happy with the new wrap, good for her on a job well done.