Well, I will wade in with my results. I've done both a frozen roast
and frozen chicken parts, breasts to be exact. Had perfect results
each time and nobody died or even got sick. Mine is a West Bend
rectangle slow cooker/crockpot that sits on a separate heating unit.
The dial goes from 1-5 and I pretty much cook things on 3 - 3 1/2. I
didn't try browning it first and it turned out great. Within about 2
hours, perhaps a bit more, of expected dinner time I chunked in a
bunch of veggies such as potatoes, carrots, whole pearl onions, and
fresh button mushrooms. From start to finish was 8-9 hours, depending
on the size of the roast.