I've made my own perches for two cages now. I use the hanger bolt and 2 nuts with a hand wrench. I drill a pilot hole first, and then work up in drill sizes slowly so I don't split or crack my wood until it's just under the size of the hanger bolt. then I hand tighten the hanger bolt in using two nuts as a surface for my wrench. I like to do it by hand so I can feel things out vs a power tool.
to find hanger bolts you either have to order or look around the more "mom and pop" hardware stores. I have found that walmart, mernards, home depot, and lowes don't carry the right stainless steel ones.. at least in my area. I've had better luck with Ace and tru value hardware stores.
If you are using branches with a questionable or unsafe bark, soak them in the tub for an hour, and then a potato peeler works amazingly well at slicing off the bark.
As for "sanitizing" I always soaked mine in water and vinegar for an hour and then baked them in the oven on 300 for about an hour, then turned it up to 400 for 15 min. No idea if it was useful or not, but I always felt better about it. lol