I think you should serve cold cereal - with milk if there is any left, without if Buck drank ti all - for dinner when Buck has eaten all the ingredients. THe whole big sigh, this is what we have for dinner now Tony. Buck ate this and this and this and this and this and this and we just don't have anything left.
If you have a camera on your phone and you can print out a picture from the computer, take a picture of those knives that he has ruined, take a picture every time they are on the counter not in the sheath, and of every toher thing he is destroying and post the photos in your room where Tony will see them when he uses the bathroom or gets up or whatever. Keep adding to the wall of things Buck has destroyed and before long Tony will start being as ****** about the cost of a Buck in your house as your are. Be SURE to ptu the $$ value of each item that Buck destroys on the picture. I would be SOOOOOOOOOOOO tempted to set a $$ amt ($2000 or $400 or whatever is your abso max you are willing to spend on him) and make one of those thermometers that groups use to show how much they have raised toward a goal. Where you color in up to a line to show $100 or $200 or whatever (our United Way and many toher fundraising groups use these to help raise $$) and it would show exactly how much Buck has cost you. LIke the $180 in grocereis that he ate $150 of in 3 days? That would go on with a picture fo all the trash from the empty packages.
It would be a visual to help get Tony to live in the real world and to realize that as long as he allows Buck to mooch, then Tony won 't be able to afford a dr for his problems and those are SERIOUS so Buck needs to go.
For meals I would NOT use color coding. Buck will be "confused" or he will just move the dots from what he wants andput on the color that says he can have it - then YOU will get blamed for markign it wrong. Put an X on anythng he cannot have. Give him a drawer and he can ONLY eat what is in that drawer. Put the X on everything else (even every egg because a number on the package assumes he can count. He will take 4 eggs now, and 4 in 2 hrs and 4 2 hrs after that because it said 4 and he "forgot". So put an x on each egg or indiv item that he cannot have. Then TAKE PICTURES OF EVERYTHING YOU PUT AN X ON. It will get to that point, so go there now with your smartphone. Document the date, and show the x's so you have PROOF because Buck will try to tell Tony that you didn't have an X where he could see it or you didn't have it there at all. So document NOW.