My opinion is that once a gift has been given, the giver is no longer in control...
That said, if there is some special reason the giver wants to retain control, then maybe a conditional gift should me made. Something like, "Darling Nephew, I would like you to have Departed Grandpa's favorite diamond cuff links. I'd like them to stay in the family, though, so if you ever tire of them, would you please give them to another member of the family instead of discarding or selling them?" I myself would not think that that is rude at all.
My wife and I learned the hard way years ago that a cash gift certainly can be used differently than intended.
Shortly after we were married, before we had children, my wife wanted to buy her aunt a burglar alarm system. (That particular aunt had just recently been divorced from an abusive alcoholic who had beaten her and who had threatened her and her children.) My wife had talked it over with her aunt. The aunt said that while she couldn't afford the $200 or so it would cost to install the alarm system, she could afford the $15 monthly monitoring fee. She said she was afraid of her ex-husband and she thanked my wife and me so kindly when we gave her a check for the $200 installation fee.
A couple of months later this aunt invited us over for supper. When we arrived, I was curious, so I glanced around, looking for the alarm system we had paid for. I couldn't see any sign of it, so I asked. The aunt replied that she had thought it over and had decided that replacing her broken dishwasher was more important to her than installing an alarm, so she used the $200 as a down payment on a dishwasher.
My wife and I pretended to be fine with this (at that point we felt, "What good would it do to protest?") while we visited in the aunt's home. But when we got out to our car my wife and I had a long talk and decided that we would never again trust her aunt with cash. (We were so upset because while we were willing to give the aunt $200 of our hard earned money for an alarm system to protect her and her children, we would NOT have been interested in giving her $200 toward a dishwasher. We felt like she should wash her own dishes instead of tricking us into paying for a dishwasher.)
We resolved in the future to make the check payable directly to whatever use we want it put...