For a while I was catching 2-4 squirrels a week with traps in the backyard, that might be an option also. Traps have the advantage of not requiring you to actually be there for them to work. A trapping license was suprisingly cheap, too.
I’ve built three small “squirrel condos” that are mounted in our cherry trees out back, and our local squirrel population is robust.
My thought on squirrel bounty WTSHTF is to offer 5 .22 shells per squirrel...good way to promote marksmanship and start fostering a barter economy.