Regarding using spray silicone on housings and buttons, 2 issues:
- I've heard that it can cause a problem with lexan housings, it can permanently fog or distort the surface. Not sure if that's true and I can't find any reference on it right now.
- It's too thin and runny. Yeah, that can help it get down the shaft to the oring, but you want a thick grease that stays in place, not a thin runny product that can evaporate. It's like replacing the axle grease on your car's wheel bearings with wd40. It's just not gonna last that long, and it will dissolve the thicker grease if you ever try to go back to the good stuff, so you'll have to clean the thin stuff off if you want to get the thick stuff to stick.
So how do you get the thick grease to migrate on the button shaft and get to the oring? Warm up your housing. Not hot, just warm. Soak it in warm water.
I've had a lot of housings over the years. Ikelite, olympus, nauticam, gates, light & motion, sealife... for me a sticky button is just a sign that the button needs service, the lube has worn off. Sounds like a more serious issue for others if it's happening right after a service.
When I'm on a trip and need a quick and dirty fix, what I do to service them is to mop some oring lube onto the button shaft on the inside. Warm up the housing, push the button in, and on the inside of the housing, mop some silicon grease onto the shaft and then push the button about a million times until the grease migrates up the shaft onto the oring. I use the edge of a business card to get the lube onto the shaft as close to the hole as possible. I use a lot, I try to build up a fillet of grease all around the hole so the shaft will drag it in as it works. It makes a mess. I clean it up after with a q tip.
When I'm home, I just remove the e-clip with a pair of bent needles nose pliers, remove the button and the rings, clean and grease everything, and re-assemble. DO NOT DO THIS THE NIGHT BEFORE A TRIP. DO NOT DO THIS WITHOUT TIME TO GET SPARE E-CLIPS AND ORINGS. YOU WILL LOSE ONE.
I CANNOT SAY THIS LOUDLY ENOUGH: YOU WILL ABSOLUTELY LOSE AN E-CLIP EVERY TIME YOU TRY TO DO THIS. DONT DO THIS WITHOUT SPARES ON HAND, OR WITHOUT THE TIME TO ORDER A REPLACEMENT CLIP.
These tiny parts jump around and get lost, I don't care how careful you are. The e-clips get bent, sometimes you can bend them back into shape, not always. Some say they should always be replaced. If you are going to try this, you are going to need to have spares on hand. Either order some e-clip and oring kits, or measure what size you need and order a bunch of them. Look on amazon for e-clip kits and oring kits. They have e-clip tools, I've always gotten by with small needle nose and heavy tweezers.
McMaster-Carr has a good page (as usual) on e-clips, with dimensions of the clips and shafts, so you can easily figure out which size you need: