Hi Ef, I Love Bt! But it's still illegal here in Calif. I've been getting Bt from a good source for the last 3 or so years, but that source is taking a big risk mailing it to me, so I'm on the look out for another source all ready here in Calif. I have friend who runs a bug and termite business, she's going to check into getting some.
I have some frames locked up in some large plastic totes. Until I get some Bt, I'll take those infected frames and put them into the freezer for 48 hours. That works like a charm as well.