perhaps they could start a program where everything is taken care of, all they need to do is do a training course on how to handle a pony, turn up and gear the pony up and race.
I'm not sure how many would turn up and get inspired, but if it was more attainable and there were signs around telling kids and parents it was possible, maybe there'd be more interest.
When I aged out of the ponies, a girl used to drive my pony. We provided everything, she just got him to the trots and drove him. She came from a horsie background so had a float but I'm sure the clubs could work something out with pony owners