I know this thread is a little dated, but I wanted to chime in too because I think there is a lot of good information and interesting hypotheses related to what's being discussed here.
From my experience working with clowns, there is no way for me to identify, with 100% certainty, which animals carry the clown gene from those that do not. I agree that het clowns often do influence the "look" of a snake, but I don't think that it can be used as a generalization for all het clowns and definitely not as a way to sell a possible het as a 100% het.
I can lay down a few examples of snakes in front of people, some that are hets and some that aren't, and the difference may be so minimal that it could be regarded as a natural variance in the morph or combo. I've hatched out some amazing possible het clown combos that I would bet money they were carrying the gene, but I wouldn't gamble my reputation on it.
It would be an interesting, though lengthy, experiment for someone to test their theory on identifying het clown genetics and I'd love to see what the results were.
Good stuff!!
Thanks,
John