Why bother then? Just hand them a flower and watch them terrorize.
Check it out:

British soldiers have been told not to shout in terror suspects’ ears, use “insulting words”, or bang their fists on tables or walls during interrogations, according to a published report.

Britain’s Sunday Telegraph obtained court papers outlining regulations for military intelligence officers, and current and former commanders have warned that the guidelines are so strict as to make interrogation pointless.