It occurred to me while I was writing the post below on another thread that I;d never shared it as a topic heading.
Another book that may be VERY helpful, even though it was written for caregivers of elderly people with dementia. (The skills base it teaches is close to identical for caretakers of sz pts, at least with respect to managing the relationship between you and them when they are delusional.)
And once you have that skills base, you can add this one to get a very effective collection of skills for dealing with such people.