I gave Waggy a thorough bath with medicated shampoo, and hopefully managed to get rid of all the poo that had gotten matted into the fur around her back end. She was starting to smell quite ripe, and the poo-mats were preventing me from trimming her fur. The best strategy that I've come up with for washing her is to fill the bath with warm water, strip naked, put on a waterproof jacket and trousers and get into the bath with her. The waterproof gear stops her from scratching me when she tries to climb up me to escape, and it's easy to rinse and dry afterwards, though fortunately her escape attempts are becoming less vigorous now that she's getting used to the concept of bathing.
She used to run away from the electric shears and cower, but these days she'll happily run down the stairs and jump up onto the window ledge where I trim her when I call 'hair cut' to her, since I've conditioned her associate it with getting praise and a treat at the end, so hopefully she'll become equally cooperative with respect to baths.