Hack your Sleep: Sleep for 2 hours everyday

This comes up every few months on HN. Does it work? maybe for some people, but your sleep cycle will be so different than anyone not using this system, it will be difficult to implement.

"You can train it to enter REM for short periods of time throughout the day in 20-minute naps rather than in one lump at night."

How can this possibly work unless you are in college or own your own business?