Some things I've heard
paper bag trick
braining
thawing over the enclosure using a hair dryer
thawing in warm chicken stock
also try a Gerbil cause it's closer to their natural food source in Africa
I tried a Gerbil once and he hit that sucker so hard like that's what he was waiting for.

Good luck and keep us updated on what works for you

P.S. I've heard of BP not eating for up to a year with no problems so don't sweat it.