Distance is sometimes the only language repeated disrespect understands.

Words have already been tried by the time you get to this point. When disrespect keeps recurring after being named, distance stops being punitive and becomes the only remaining way to communicate that something is not acceptable. It works because it is not an argument.

Before going quiet, be sure you actually said the thing once, clearly. Then, if it continues, reduce access without a speech. The absence carries the message better than another conversation would.