Years ago, Lufthansa used to issue a set of stickers to their business class pax to indicate:
Wake me up for meals
Wake me up for Duty Free
Do not Disturb
One placed the relevant sticker on the side of the seat.
Maybe the OP needs one saying "Wake me up if I am snoring loudly"? PYOSS, as well as PYOBP?
I snore heavily (according to Mrs FD, anyway) and am unable to afford a private jet for the sake of my fellow travelers. I do, however tell the CC at the start of the flight that it's OK to wake me if I am being too loud!