If I remember correctly, messing with sleeping habits (telling them they had 8 hours sleep when they had 3, putting them on a variable length day, etc.) and get

If I remember correctly, messing with sleeping habits (telling them they had 8 hours sleep when they had 3, putting them on a variable length day, etc.) and getting their body off cycle is more effective. Depending on who you are, that might be torture or it might not be.