I worked at KJAX Jacksonville, Florida for Delta. Like the post above me DC9,s MD80,s would some time power back, But the Turbo Fans that are on most of the other aircraft are just to strong to do that to. In some cases it is actually not good for the engine to be used in that manner. That along with the amount of thrust It would blow out the windows at the gate and you with them.
The B737 series that Southwest uses we used to call over sized vacuum cleaners. The bottom of the engine is not that far off the ground and it will suck up anything not permanently embedded in the ground. It used to amaze me watching the engines of a B767 suck up the water off the ground while in flight idle and these engines are at least 5 feet off the ground.
Jet intakes and exhaust are nothing to play around with. Get to close and you might wind up as ground human.
I have seen a L10-11 suck a empty off container of a container carrier and it was locked in good. It wedged in the nacelle, needless to say we had to have the plane shut down the engine down and a mechanic had to examine it for damage.
I once watched a DC9 that was powering back come with in inches of going off the tarmac which would have resulted in the plane sitting on its tail with the engines running bad things could have happened. It scared the you know what out of me. That was to close for comfort.
