I have some beavers that I was hoping to use for Bobcat bait but they don't seem to be attracting any Bobcats. They are froze solid pretty much. I axed into them some to open them up a little. Do you think I should put some salt in the openings &/or maybe rub some of Dobbins' bait solution on them?

I would stay away from the salt.it will make the bait smatchy and wont be atractive to the birds and small microtines which are a major attraction at a big bait to your target animal.Feathering the big bait with your axe will make it more attractive to both small birds and mammals as well as the target animal.
Salt also draws in ungulates which you definitely dont want around your sets.

Well then maybe rubbing it in bait solution, or perhaps glycerin, would help