I heard that in any production where chocolate is an ingredient, water can’t be used for kashering because even the tiniest bit left behind will ruin the whole batch. Instead, they use fruit juice to kasher the equipment.
A Rav told me to avoid certain brands of chocolate liquor because of this and to stick only to those made in factories that are kosher year-round.
Is using fruit juice instead of water a halachic leniency, or is it considered a proper solution? Would love to hear your thoughts or any sources on this.