Well it won't hurt to boil it. I would assume that is to make sure nothing is alive and that will only take a minute. It could be that it will help it to remove tannins, or to help it sink but I don't know about that.
It is supposed to speed up the release of tannins and kill any unwanted parasites. I dont know how long you could boil it for, long enough to kill any parasites I suppose. OR you could leave it the sun for a few days then soak it for a few weeks to get rid of the tannins and you should be fine. Either way is effective. Btw I have never boiled my drift wood, not by choice I will have to mention (It is pretty hard to boil a 3 meter long piece of wood).I also like the colour it leaves in the water. :hi: