Cure this with the Guest Gizmo. It has a cough drop (ahem) button built right in. Your guest feels the need to make disgusting noises and pushes the button until the urge has passed. You’ll want one at every guest microphone position. The cough button is a necessary tool.
You know those cool new mic arms with the built-in LED tallies? They’re all the rage. Problem is lighting them up. Guest Gizmo to the rescue again. Hook up your mic arm to the logic port and the button changes from cough to on/off/cough and drives the red light whenever the mic is hot. Cool?
The Guest Gizmo uses your mixer’s microphone insert jack to provide the muting function. A cable with a ¼ inch TRS plug at both ends is all you need. The muting is done with a sealed relay with isolated gold contacts. Because these are dry contacts, you can even use the insert jack to drive muting logic on a broadcast console if you have one.