as long as you had the bucket full enough so they couldn't touch and couldnt climb out, I'm sure it would work. I've never used it for squirrel, but Ive done the exact same thing on mice. 5 gal bucket abt 1/3-1/2 full with a stick from the outside up to the rim, and a handfull of cornmeal in the water is definitely a good mousetrap.