JimLap,
Do you do any of the servicing for your store? This obviously depends on how deligent people are with their equipment, but I've seen as high as 80% of regs in for service having some form of internal first stage corrosion.
DVT provides the benefit of keeping water out of the first stage inlet chamber in many more situations than the most obvious dunking it in a rinse bucket without the dust cap.
Do you rinse your reg attached to your tank and pressurized? If not, water is likely to get past the dust cap. It is called a dust cap, not a water cap for a reason.
Do divemasters fill your tanks on board a boat between dives? If you're not making sure that you're capping your first stage each and every time, chances are you'll get some water entry. I am consistently amazed by the number of first stages without dust caps in place I see removed from the valve waiting for a fill on dive boats - all while the boat is underway, with spray coming over the deck and dripping wet divemasters hanging over your gear.
Do you believe that directing air from the cylinder valve into the filter and dust cap is going to keep things nice and dry? Chances are you're blowing water right into the reg.
I don't mean to jump on you Jim, just wanted to take advantage of my opportunity to dispel the the rumor that DVT is only for people that accidentally rinse their reg without the dust cap.
Doug
