They paint them, or at least parts of them, with urucum (reddish) plant dye or even their own blood if there are no urucum plants nearby.

. . . a sort of little back kitchen, where dirty work, such as washing up dishes, might be done.

The controversy gave a boost to the author's sales.

Aldhelm is a hard author. His 'densa silva latinitatis' [dense forest of Latinity] is close to impenetrable, and his proverbial verbosity doubtless has led the most chalcenteric readers to wonder if there was any reward at the end for their pains.