You could stick hidden camera into the can ...

I read,  most 'secrets' are usually revealed  when one's taking a dump. That's biology ... 

Put a gopro up your bum.

not a creepy question at all 

got to love the new 'alias's' !

be sure to use a heat senstive / infra red camera.
that way you can see EVERYTHING.

and be sure to put camera's EVERYWHERE.
it is not as if you are coming across as some kind of pervert at all with this question.

do like Costanza did and put a tape-recorder in your briefcase,,,  haha,,, smooth move George,,,  smooth move....