I was just discussing this with Matthieu yesterday. The best way is to prevent the problem happening in the first place. I rinse down my suit with warm fresh water every dive and then usually about once a month I fill the bath with warm water and flood the suit entirely and let it soak for a few hours even overnight. Hang it up and let it dry, turn it inside out and repeat. You won't get the boots turned but you can roll up newspaper to dry those out. Be careful with the zip but you don't need to be overly delicate. Yes it does take several days to dry in a nice warm ventilated room especially if its neoprene.
I've never serviced a chest valve (never had to). However the manual inject buttons on the rebreather counterlungs work with the same principle. There's springs and o-rings in there and plenty of places to accumulate and trap grot. Disassemble, clean, replace o-rings, lube, assemble, test....(repeat
)
Do you use talc? Get rid of it - likely candidate as to whats caused the problem in the first place.
Likewise the silicone. Where are you going to put it? You might be just sealing in the shite thats accumulated in the valve!
Just my 2c
