Tom when I built the WH Edge I had problems with the gorilla glue foaming out and getting in the hinge knuckle and making them very stiff. Had to work with an exacto for a while to dig out the glue LoL, so this time I wanted to make sure I did not have this problem.
I made very certain that I cleaned off the hinge shaft with denatured alcohol prior to glue application. I give my control surfaces a BIG pull after assembly and trust me these puppies are not going anywhere that it doesnt take half the wood in the wing with them LoL.
I do echo your concern for having a clean glue surface though, one must take precautions to keep the glue surface absolutely clean and lubricant free.