After years of soaking regs off pressure here is my .02.
Get yourself and o-ring sealed or rubber dust cap.
Put it in place.
Don't push the purge button on your 2nd stages.
Soak for 24hrs.
Rinse.
Air dry.
Fresh water won't hurt the inside of your 2nd stage (think dangling octo's).
Fresh water won't hurt inside your 1st stage.
Its when you have salt or dirty water that can plug up your filter is the problem with getting water in to the 1st stage.
Also water in your 1st could be forced in to your SPG and cause real problems with it.
Get yourself and o-ring sealed or rubber dust cap.
Put it in place.
Don't push the purge button on your 2nd stages.
Soak for 24hrs.
Rinse.
Air dry.
Fresh water won't hurt the inside of your 2nd stage (think dangling octo's).
Fresh water won't hurt inside your 1st stage.
Its when you have salt or dirty water that can plug up your filter is the problem with getting water in to the 1st stage.
Also water in your 1st could be forced in to your SPG and cause real problems with it.