How do I turn a dairy popcorn maker into pareve
There is no need to kasher the popcorn machine. The reason is since the machine was not used within 24 hours, and the taste of milk would only be nat bar nat, it is permitted l’chatchila to eat food from it after eating meat, and since we never eat popcorn together with meat it is not a problem at all. Therefore just clean it around from the butter etc. or any residual oils, and you can use if for pareve.