The vinegar method works for spaghetti stains, too. If you want to try a different method, bring out your baking soda. With some kind of brush or a very scrubby sponge, you’ll want to scrub the tray down with a paste made of water and baking soda.
Baking soda helps to lift up stains and food particles, so you’ll be left with a squeaky clean high chair when you’re done.