Or you could go down the RAF Regt route of picking someone with a vacant look, pose a ridiculously vague question, pounce, and then spend 20 mins taking the urine for getting it wrong.
We had that during an AIT lecture. The Helo ALM was brieifng the motley assembly of aircrew on swash plates. One Tonka nav looked generally vacant and bored.
The ALM pounced and we had a wonderful Bob Monkhouse moment.
Bob Monkhouse in Privates Progress was day dreaming during a Bren Gun demonstration. William Hartnell pounced and made him reassemble the Bren which he did in short order. Then he confessed he used to make them.
After Tonka mate answered the questions correctly he admitted he had worked at Westlands.
The moral, be careful who you ambush.