I tried it… I couldn’t get past the first 3 days 
I think its 3 hours of sleep and the 20 min naps. every 4 hours. 3 hours for the deep sleep… and the 20 min to recoup the REM.
I think davinci would take his naps in a chair with a spoon in his hand, when he would sleep and drop the spoon the nap was over it would wake him up