In that case, leave the servo pot on, and adust it so the alarm only comes on when you put your throttle in the cut posistion, then use a Y lead.
I did get a propper one for gliders before i found this set up, turns on as soon as the tranny is turned off and works in any channel. was only 6 pounds, going to put it in my glider when i re-tape it.
A hint i learnt from gliding is to keep my eyes on the glider as it went down in the dunes, then take a bearing from the horizon and walk in a straight line untill i found the glider, you get better at this after a while.