how to make a drink item

The only way I think this is easily done is by making it a potion. Make the effect of the potion do whatever you want the drink to have.

^ The problem with that is then you can't have custom items, and are forced to have splash and lingering potions, as well as a tipped arrow.

I've tried setting a food item's animation to drink but that does nothing.

^ That issue managed to fix itself, setting the animation to drink makes it work now, however the end of the drinking animation still  plays an eating sound. Changing the item use time doesn't help either.