OC you're thinking of cauterizing(sp?) a wound.
that heat is generally much more intense then something that comes out of a glue gun, although you can also use acids such as silver nitrate (I've had about 10 sticks of that used on me at one time... NOT PLEASANT).
In that case, yes it is beneficial because you are burning the wound itself, which brings more blood to that area and spurs healing. It also clears out any infection.
In olden times, people would generally put a metal rod in a bed of coals and then apply it to the skin (that scene from braveheart after the pull the arrow out of the old man for example).
your basically charing a very small amount of tissue (which does turn grey and slush off... it's gross) to inspire the skin beneath to heal faster.
I've had that done, as I mentioned with silver nitrate on more times then I care to count, sometimes using up to 10 sticks of it. Silver nitrate has become the more popular way to cauterize wounds and can be used on canines also... however best a pro do it and it's not likely to have a supply of silver nitrate at home.
The process is not instantaneous and would be useless to re-attach an ear... if you wanted the tissue to heal where the ear was, then yeah this would be a good idea.