(Same area as you) I saw them at boat or RV show, can't remember which. I thought about them for awhile but after thinking about it for some time and not sure if I really have any problem, little alone their price, so I passed. I do keep pretty good track of humidity inside RV and store rv correctly, atleast in my opinion. Mold is everywhere, just that we get more than other places. Easy to keep on top of. Before spending $$$ on that I would read all I could about mold. Basically mold doesn't grow well in certain conditions. And those conditions that don't foster mold growth is what I try to keep RV in. Of course there are some people that sensitive to mold that have to take other precautions. Here is a site from your wonder state goverment about mold in our area.
https://www.doh.wa.gov/CommunityandEnvironment/Contaminants/Mold