Hi all, I used to work as a jailer in a fairly large county in N. Texas.
As far as practicing slide removals on an officer's weapon, I've never seen ANY confinement facility, county or state, that allows officers to carry their sidearms past the checkpoint. The inside of every facility I've ever seen is a "no-gun" zone of the highest order -- we're talking instant termination (unless you're a certain Lt., but that's another story....)
So I seriously doubt inmates in the facility are actually practicing on real weapons. Now the other side:
Inmates have a <i>lot</i> of free time to do stuff. They improvise suprisingly well. We often commented that if some of these clowns would put the same ingenuity into making an honest living as they put into taking from society, they would be millionaires.
Fashion a mock Beretta from a bar of soap? Honestly, it wouldn't surprise me a bit. I've found some pretty amazing soap sculptures during shakedowns. Personally, I have more interesting things to do all day but I'm not locked up, either.
And yes, they do teach each other and they do practice techniques to defeat law enforcement officers. Fortunately for the good guys, most of the techniques are based on urban myth, armchair martial arts experts, and "my cousin's friend did this and got away." <b>Un</b>fortunately, some of it works. Be careful.
And, in my opinion, if they can get their hand on your gun to release the slide, they can also twist, rotate, and disarm you in the same amount of time. Don't let them get that close.