Yep, you've got the idea. Just be sure to enclose the back side of the switches so somebody can't look at them and figure out the sequence. The more positions, the better, so there are more possible combinations.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!