IIRC, they've got an enclosed back porch, right off the kitchen. They could set that space up as a bathing area, with Juliana's shower stool, and use 5-gallon buckets of hot water to give themselves baths with a washcloth (I think the laundry area is right there, so hot water is available). If there's a utility sink out there, they can hook a sprayer attachment to it instead of using buckets. Hang some curtains up for privacy, include a space heater for cold days, and figure out a means to keep the water contained and channel it outside (a kiddie pool, or plastic sheeting draped over something that would create a raised edge, would do fine). If either is too fat to wash her hair at the kitchen or laundry sink, she can still do it while bent over a bucket, scooping clean water over her head from a second bucket.
There is absolutely no excuse for being as filthy as Corissa has been lately. NONE.
Adult Protective Services can't be bothered with these two, by the way. They aren't considered disabled, aren't dependent upon a caregiver, have a house with working plumbing/hot water, and are legally competent to manage their own affairs. That Corissa chooses to be a filthy slattern when she is capable of working out a means to stay clean is entirely her own doing, and nothing local or state government needs to get involved in.