I missed the turn in discussion....what minwax product are you folks using?
guessing a polyurethane perhaps?
I'm not so sure a coating like that would be the best idea. Even coatings like flex seal....
....because eventually any coating will almost certainly leak. Water gets behind it then has a hard time getting out.
when mine ever leak again...or maybe even preemptively before that happens some day, I plan on most likely using rot doctor...or maybe one of the similar products available...a very slow cure epoxee designed to soak into the wood and encapsulate the fibers from within. I don't know, maybe that's no better really, but it seems to me that it probably is....
and I figure I'll probably some day vent that cavity into the bedroom so that it has a chance to breath...(or an alternative I've considered is to fill the cavity entirely by epoxying in a block to completely fill it then covering with a surface mounted fixture)
....I'm still kicking myself for not having them use better surface mount fixtures and eliminating that cavity cut out when they replaced that entire wall under warranty!
Oh well....so far the overkill caulk and seal job the bodyshop did is showing no signs of leaking... yet...