It was a great move but Dan waited until his back was against the wall to do anything and then he really needed to count on Frank's gullibility.Dan could have gone to Frank much earlier. As soon as frank won the veto last time in fact, Dan could have started working on him.
The same with Jenn. He knew he'd have to pick veto players so he should have gone to her and made a deal before she talked to Frank. It would have been so much easier for Jenn to refuse the slop pass and let Dan win veto.
A plan is much better than a Hail Mary.