Both of my tanks have gravel and I feed sinking pellets. Well the pellets, in the feeding frenzy, would get buried in the gravel or fly everywhere with the current. It would then other be sucked up into the filter or just disintegrate in the gravel. So I had these 6 inch flower pot bases (you know the ones underneath the pot that collect excess water when you water your plants) that I had just bought and leftover tubes from an under gravel filter that came with my tank. I put the base in the tank (after washing it thoroughly) and covered it with a very thin layer of gravel, just enough to hold it in place. Now when I feed my goldies I put the tube into the water over the food dish, dump the pellets in the tube, let them sink, and remove the tube. It keeps the pellets in a concentrated area and doesn't let them go deep down into the gravel. The goldies can easily move the gravel on the plate to access the pellets. Plus if you have issues with some fish not getting enough food during feeding because of other dominant fish, you can set up two of these, so each fish will have their own dish.
So, you ask, does it work? Well, my fish now rush over to the feeding dish when they see the tube enter the water... I have one 7 inch oranda that rams it the minute the food gets close to the bottom . The first week it was in there, the more dominant goldies actually staked out claims over the dish, they would even nap in it. Nowadays during feeding time, one tanks fish takes their turns eating from the dish whereas in the other tank the two dominant fish circle the bowl wrapping each other with their tails while the smaller guys merely take what they want. ("No my food..." "No, MINE"). Plus I no longer have issues with filters clogging before their weekly rinse.
Couple things... try to get a high sided flower pot base, because lower sides will allow food over the sides. If the edges of the base are sharp, just roll them/blunt them with a pair of pliers so your goldies aren't cut. You can purchase a clear base if you don't like the artificial look of the dish. Oh, and the bases range from $.50 to $1.60 at any gardening center. I am not sure about the tube, but I am sure you can find it at any major pet store or hardware store.
Thats it... Goodluck!