Don’t know if it would work or not, but I’ve wondered about a mylar bag combined with a nylofume bag, with a linen satchel filled with activated carbon in between them. Food goes in the nylofume bag, tied up well, then put into a mylar bag with a satchel of activated carbon also in same and then closed up. Course, it would be helpful to have a little ziplock bag for the activated carbon filled satchel to put it in for when the bags are being opened up. The less it’s exposed to moving air, the better and longer it will last.
I figure we shouldn’t let perfect be the enemy of good in such cases. Sure, we can debate about how many large and/or small molecules can dance on top of a quantum pin head till the Grizzes come home, but imb, every little bit helps.
I don’t happen to live anywhere near any Grizzes (though fairly close to a very high density Black bear population), and so wouldn’t be able to test it with them anytime soon, but a number of you folks do, and you could run some experiments while putting this combo in Ursacks or hard containers.
Set up one of those wild life trail camera’s like Kattt uses to get pics and vid of Mountain Lions and other critters. Put a lot of human smell around it in various ways. Rubbing your scent on it, maybe leaving some well handled items near, peeing near the area, and the like. “Refresh” as needed.
Over a period of time, might give an idea of how well it works or not?
I might try similar with Black bears on my end, but would try to minimize the human smell more so.