Can you disown your son so that he shows up as an adult whose family does not make any money . That way he would be eligible for aid and grants ?
It's not that unusual to find wealthy parents that refuse to help their children at all, even though they didn't do anything, and are fine people. I'm a bit unsympathetic to OP, but the young adults that have literally nothing thanks to the whim of some asshole... that's really tough, and a flaw in the system.
Anyway, there are rare cases, I believe, but the government makes this very difficult. If you grew up in a normal household, live an ordinary life, but your parents refuse to pay, you're out of luck. You will struggle to get this even if you're estranged from extremely abusive parents.
It seems like home equity does not count these days, which is an improvement I guess.