Dead caterpillars will be fine. If I'm diligent, they'll hatch tiny, eat the BT, and die tiny. I'm going to wash the cauliflower off anyway.
This place says DE is effective against caterpillars:
http://www.absorbentproductsltd.com/...sect-list.html
I asked Tormato for a couple seeds of Romanesco, so we'll see if it grows for me. I bet the advice I get here for cauliflower will go for romanesco too.