That wouldn't defeat Hidan, he is immortal.. he can have someone re-stitch his head when the fight is over, Tsunade would simply be dead.
Hidan would get a hold of her blood before Tsunade gets serious and tries to end him.
Katsuyu is the answer. If you do some research, a person can live up to 30 seconds with a severed head. That's enough time for Katsuyu to stick it on her shoulders and the Mitotic Regeneration does the rest. And how will Hidan really be able to move after being swamped in a lake of HIGHLY corrosive acid? Even if he has Tsunade's blood, she can tank the acid spray with her Jutsu.
And another note, if Hidan gets her blood, that's one thing. but it takes Hidan TIME to MAKE A DIAGRAM, LICK THE
Link me a Manga scan of Tsunade doing anything else in combat other than her uninteresting, boring, and vulgar "Hulk Smash" act.