Cheap microphone mute switch
Check out this tutorial on how to make a cheap mic mute switch. I use two of these one for my vocal mic and one for my cajon/percussion mic and this allows me to turn them on/off with a footswitch which stops the dreaded mic bleed and feedback when recording into Loopy.
When I'm not recording from the cajon or vocal mic they are off and not accidentally recording background noise, and even worse speaker sound back into Loopy. Works a treat. I actually didn't use a damper pedal but an old amp switch pedal with two foot switches on it, one vocal and one cajon.