Disambiguation, removing multiple readings

Somehow, I cannot find a method to drop all invalid postags for a word.
Filter seems to add a tag when no hit; remove does not accept regexp.
Multiple disambig lines are also not allowed.

How can I do this?

We have e.g. <disambig action="remove" postag="VER.*"/> in German, so regex should work fine.

So without postag_regexp. That is not what I expected. I will give it a try.