IIRC, you can right-click on a photo and choose "show in finder" to see where it's really, truly stashed. Trash these, empty trash, and they're really gone for realz. This may or may not be accurate, but I think it still does the trick.
I still have horrible memories of the grotty homemade porn I found in a used Macbook I bought from an acquaintance a while back...
I nuked the hard drive and reinstalled OSX. It was the only way to be sure.
1983 Suzuki GS850G, Cosmic Blue
2002 Suzuki Vstrom DL1000, Midnight Blue
2005 Kawasaki KLR685 - Turd II.2, The ReReTurdening
"Do not crinkle your food wrappers loudly. Be considerate to others, or I will bite your torso and give you a disease."