Het males aren't really worth it for a breeder to keep. Het Pied, Albino, even clown males are only worth $50 on a good day. If you end up keeping it for more than a month or 2 you start losing big, food, bedding, rack space, etc gets expensive. I know a lot of local breeders that sell 100% het males to pet stores.

The cheapest way to prove out your snake will be to get a normal female (or a few) and breed him to them, hold back all the female babies and breed the father through them all again. If he is a Het for something, then it should be passed onto half of his babies, you'd have like a 12.5% chance per egg of producing a recessive (if the father actually is a het)