I eat the skin, or at least most of it. Then I lay the foil in such a way, the fire burns up any remains. I make a point of not being down wind as I don't want my clothes saturated in anymore food odors than necessary.
Lk Trout being an oily fish "probably" contains more oily residue than so called drier fish. At least that's what I tell myself.

I leave the foil in fire pit until next morning and then roll into tight ball and put in zip-lock garbage bag, inside plastic liner of my food pack.
Since I hang my pack, I don't worry about odors from the fish foil anymore than I do from my packaged food, which is not vacuum packed, but stored in Zip-locks with the air squeezed out.