Just from the physics perspective, kind of yes... - BUT: it's essentially a petri dish for bacteria and funghi. Also, it would still dry rather quickly, leaving a very sticky, matted mess of fur and whatever they come in contact with, coating the ears, reducing the heat flow. It would only make some sense when you have to cool down rabbits in an emergency, but simple water will do that well anyway.
I think the system of blood vessels and skin is pretty much optimised, adding random stuff has very little potential to make things better.
A cool resting place, like a stone or iron slab with cooling packs underneath, imho is a good way to cool rabbits. That's the way they do it themself, dig away warm topsoil and get their bellies into the shallow pit.