I have one, and haven't had much luck eastern with tree squirrels. Understand they work better with western ground squirrels. I have a smaller chipmunkinator, and caught 22 chippies last summer with it. Also caught 1 grey squirrel who happened by and saw 2 chippies trapped in it, and successfully got in. Squirrels and chippies don't "play well" together. Hoping to get something that'll work with red squirrels (little bastards).
This time of year there is a lot of food around, here in Northern California. They won’t enter something suspicious until food becomes scarce. Just be patient. Leave some of the food outside leading to the opening, and a big pile scattered inside, and they’ll eventually come.