Does the divorce of "consider yourself divorced" take effect if said with the intention of threatening, knowing that the wife is menstruating and has been divorced twice before, and the husband wishes to reconcile with her?

The phrase "consider yourself divorced" is an allusion to divorce, not an explicit statement of it. Therefore, if the speaker did not intend divorce by it, it does not occur. Divorce during menstruation is an innovated (bid'i) divorce, but it is valid according to the majority of scholars.