There really isn't any need to feed pinkies to bearded dragons. The occaisonal one would be nice as a treat but unless there is some speciall reason to feed them pinkies (female just finished laying eggs, to regain weight loss due ot illness etc) there isn't any need to do so.
I fed my bearded one pinky and though she eventually ate it but with the difficulty of getting live pinkies at any given time (unless you breed mice), and since there is real no need, I would recommend not bothering at all. A few waxworms now and again would work just as well.