When I was in the reptile trade, I could get a mom who's child wanted a snake, to hold one within 5-10 minutes. It's the approach that gets them. People throw a snake in their face and expect them to accept it. I would start off with me holding the entire snake and them petting the back end of the snake. Then I'd get them to hold the snake towards the tail while I held the snake, then we'd work our way to them holding the snake but me holding the head. Then I'd let go of the head and when the snake didn't attack them, like they thought it would, they'd open up to the kid getting a snake.
It's more involved than that, but that's the gist. You wouldn't believe how easy it is to get a colorful, good looking snake sale to one of these parents. At least that's my story.....