I just tried it. I can’t. I’m a complete failure. I put a lunch bag on my right hand and started playing Ballade (Salzedo), and the bag did not rip or tear at all, not even playing an aeolian flux. Boy, it must be true. Now, just imagine if you had a body-sized bag.
A wet paper bag would be easier as it would tear. It is a favorite condemnation used by musicians to say that so-and-so could not play their way out of a (wet) paper bag. Wet implying that it should be easy, yet they cannot do it. It’s like saying that someone cannot play even with their eyes open.