By the time he's got the entwine off and is ready to flurry, he'll be so maledicted or hurt that there would be no point anymore, and it would just get him killed.

entwine gives the dagger spec at least three free rounds of action, of which two are with you disarmed. Also, dirting you would fuck that flurry longer, since you can't re-wield to flurry unless you have maelstrom. And even then, good luck hitting a flurry of any real power with -15 or so strength, more if the dagger spec manages a successful stab/twist or uses a maledict from his second spec.

Basically, unless your a rager with call bloodthirst to completely negate the effects of dagger maledicts, that plan fails. Sorry.