Steve,

Do you have any pet lizards? If you have any anoles, or if you could acquire one as a pet, you can use it's poo and shed skins and even the lizard itself as a scenting tool. Or if you could handle it, you could find a seller that supplies feeder lizards. Racers generally want lizards as prey as babies, maybe since you had some luck getting him to swallow some mice parts, yours will be easy!