I've got one of those Schrader Blowgun Valve and Hose set-ups so I don't get a leak when disconnecting the DS hose,
but... since some bright spark include 'hose disconnection' in the new BSAC DTP, I've had several whinining trainees tell me their suit valves leak when they do this needless to say we leave this drill till the end of the dive (unless the trainee is working their ticket
)