As a veteran professor of getting stuck(yes, that was me holding up the trail the last time) I can assure you, no soda pop bottle will every get you un stuck. Nor will a buried spare tire(if you could manage to bury it). I read about a lot of urban legends as a youngster, and tried many. Winching from a log across a ravine as an example...NO WAY. I have had boulders bigger then my rig move! Boulders make me cringe, as they rarely hold. Aspens, never hold. Salt Cedar does though. The reason a pull pall works if soil conditions are just right, is because it digs in as you pull.

I think the key to all these urban legends is loosing traction Vs being stuck. Loosing traction ANYTHING will work. Being buried to the frame, little will work. Most of us have long since graduated beyond the open diffs and small tires of the past where these wheeling legends were born and get STUCK!