Go back to WWI - strap him down and apply just some pin pricks which pins have been laced with garlic. He will tell you everything. The fact that this was outlawed by the Geneva Convention post WWI is immaterial. He will recover and lead a full, productive prisoner life.
I still prefer the fire ants and honey treatment. THAT look on a dead body would have the muzzies chugging beer with their ham sandwiches and singing Kumbaya.