I do a brief (10 minute) freshwater soak after rinsing my housing in freshwater after every dive. I push/twiddle/pull every control twice, then dry off the outside before opening the housing. I clean out the o-ring track at the end of the day, and lubricate it. If I change the port, I do that, too. I use a blower to clean off lint and dust, and only use a microfibre cloth if marks are left after that.
At the end of a trip I will soak everything, assembled, for 12 hours and work all the controls several times. Then I dismantle everything for storage. I never use a proprietary cleaner, though once or twice I've used a very little detergent during a preliminary wash.
Taste the white powdery deposit: it's salt... bad! If I see it, I soak again. It tends to appear where there are screws or shafts that trap moisture, and it's the reason why I think that a LONG soak is a good idea.
I've used this routine since the days of the Nik V, and it seems to work.
Tim
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