Is it dry powder or liquid?
If it is powder could you use a dust pan and broom/brush or maybe grab one at the dollar store. You should be able to rinse out the bristles pretty well. Don't forget to wear your dust mask

. For any residual staining, I have(well, my landlord

) used CLR to get residual stains out of the sink basin.
If it is already mixed dye, sop it up with some old rags. Then go for the CLR.
I have also gotten fairly good results with repeated cleaning with a mixture of liquid soap, BS, and vinegar(mixed together).
Sorry about the mess