How would one coach themself out of a paper bag?
I'm not sure if you're trolling or not.
The "...out of a paper bag" comment is an often used expression that connotes a lack of intelligence or depending on wordage used, a lack of strength.
Here, these should help in understanding it:
https://forum.wordreference.com/showthread.php?t=28317
https://english.stackexchange.com/questions/29669/what-does-way-out-of-a-paper-bag-mean
If you're still not clear on what I was trying to say, I'm not a big fan of George Karl.