Benjamin Franklin had this amazing idea of having ball bearings in his hand while solving and thinking about hard problems. The thinking would eventually make him fall asleep and as he fell into a slumber, the ball bearings would roll off his hands startling him up. It is at this precipice, the fine line between awake and asleep states that most of his ideas came to life. He would start penning down his ideas in this state.
So it worked then, it works now. A 20 to 30 minute nap during the work day has a ton of benefits, including stress reduction. I don't know why it is frowned upon. I have fallen asleep many times at my desk and have been made fun of, but who gives a damn. I would rather be stress free and have some good ideas come about.