I'll also admit to losing my phone down the side of a seat, albeit in CW.

To save myself from dying of embarrassment whilst waiting for an engineer upon disembarkation, I made it my mission to retrieve said phone from seat.

Lessons learned:

1) It isn't a good idea to sprawl out into the aisle to try and squeeze your hand around the seat as the crew might think you've passed out.

2) Whatever lives underneath the seat, should stay there. It is absolutely disgusting underneath the cushion.

3) A fork from first is your best bet in getting phone out