In reference to the controlled environment.......Different agencies do it differently especially if they have a separate standalone tac team. We didn't have that luxury initially, for a standalone team so we doubled as Patrol.
Same with the Governors security/VIP team @ the State level, double duty.
So the boomer(s) stayed in the PPV trunk with your other gear. We were trained to use #9 and not to clean "too clean" and lose the "0". We didn't have to worry about any mil rank that might be anal about "white gloving" a DM piece. We even used #9 in the cans. Makes wonderful makeup, depending on firearm. lol