I recently purchased a GX-56-1A, a.k.a. the King from eBay. I learned from the seller that it was around smoke, but thankfully I couldn't tell that it had been when I got it. However, I could tell that it had been worn quite a bit and showered with quite a bit as it had a distinct smell of its previous owner. The dirt/debris and soap scum present is definitely a contributing factor. So I set out to rectify this:
This is the easiest G that I've ever had to take apart. This is due to the buttons not needing to push through the bezel. The bezel just goes over them. Also, the straps are held in place by screw-bolts (not sure what else to call them), 2 for each strap. Once you unscrew and remove each bolt, the strap just comes right out.
Now, about the back rubber piece covering the back plate:
I read on another post that you had to remove the screws to the back plate in order to remove the red rubber covering. I'm sure it's been said elsewhere, and so I'm saying it again here,
you do not need to remove the back plate screws in order to remove the rubber covering. All you have to do is unscrew the two small screws on the middle-sides of the bezel (since that is how the rubber cover is anchored to the case) and then gently lift the cover off and over the back plate screws:
From here, I used Palmolive OXY dish soap to clean all parts:
I hand washed the case, and let the bands and bezel soak for a good half hour.
Air dried/towel dried/Q-tip dried it, and put it back together. Note, the rubber back plate cover goes back on by gently pressing it back on around the screws (start on one side of a screw, press around it).
Some wrist shots
It does still smell a bit, not near as bad though. Aeration is probably required, but I am currently trying Aveeno baby wash as it has oat extract in it and it seems I've heard somewhere that oats can absorb odors too.
I hope this is helpful for King owners out there!