Barney: I wondered if Murphy's would work. I'll give it a try. Your experience sounds encouraging.
GreyQ: we are in the process of doing that now. Cleaning out all closets, kitchen cabinets, etc first. Kiltz is at the top of the list for painting supplies. Her bedroom furniture is not quite as yellowed as the picture shows, but close. I hope to clean it up quite a bit. It's all wood and in very good shape outside of the yellowing.
I guess the one good thing about her having severe dementia is that she has forgotten that she smokes.