I hate hot glue...just hate it.

I wrap my servos in masking tape and CA or PU glue (gorilla glue or other) them in, so that when the plane kicks the bucket, you can pull the servos out, unpeel the tape, and then you have a fresh servo case with no glue or foam stuck to it. I use CA or PU glue because both are lighter than epoxy, but I use CA on foamies that need to be light and we'll be destroyed within months. I use stronger PU glue if I think the plane will have a long lifespan. Let's just say I use CA more than PU....