I have a meeting tomorrow with a fire suppression guy and system design guy. We're going to be looking at doing what the OP had talked about. Capping off a wet sprinkler head and installing a self contained clean system. We're also going to be looking at putting in clean systems in several PLC cabinets, some MCC's and some VFD's cabinets. Probably about a dozen systems in all.
I'll post back with more information after the meeting.