The reflectors sold in jackets and such are optimized for the frequency and searches, meaning that they work for around 200 ft of range.
However, most electronics have circuitry/diodes in there, so you can find a Gopro/camera/ipod if you have a fairly precise idea where to look. The receiver was picking it up at about a 3 ft radius.
But the simple solution is to super glue a real Recco reflector to the backdoor of the case. Then you could find it in pretty much any situation.
