Re: garboard plug
I would stay away from Gorilla glue unless you plug the hole at the same time with a dowel and then redrill and then seal it.
I had a Gorilla Glue failure on a set of basement doors I built last year just the other night-they are weather exposed and the glue joint failed completely leaving a 2 x 8 x 72 in my hand. Thankfully I had a tube of PL adhesive to spare and in 30 minutes everything was cleaned up reglued and clamped in place.
My point is Gorilla Glue should only be used in a tight joint-it is a lousy filler and if the glue isn't in a tight joint it foams up and loses much of it's strength.
I would drill the holes oversized and fill with thickened epoxy resin (Wood flour or milled fiber would work fine) and slap a piece of tape over it til it cures. Poly resin would work too, but I have epoxy at the house
