My parents have done this. They have set up a Discounted Gift Trust (?) with them, me and my brother a trustees as part of our inheritance. They are also planning to set up something similar-sounding (designated gift trust?) to put money in to dole out for "approved" child and grandchild expenses - again, with them and me and my brother as trustees - that has a sort of informal mission statement.
Sounds well dodge to me, but happy to give you more info if I can.