I've used vegetable oil or water on mouse tail pieces. This should be a last resort. When ever I have a hatchling that doesn't want to eat I use the following, in order. Live pinkie, lizard sented live pinkie, Brained pinkie, pinkie head, pinkie sented with chicken broth, live anole, force feed 1/2 inch piece of mouse tail. I always feed problem feeders at night in a deli cup in the dark.