OS X :: How To Disable The Dock Hiding Option

I'm the computer teacher at a school and I'm trying to lock down the computers somewhat so that the kids don't mess with settings. When they inevitably do, I waste time restoring them to normal so that other kids aren't confused.

I've used software like TinkerTool and Deeper to prevent modifications to the dock icons. The main accounts used by the students are parental controlled so that they can't access System Preferences. I turned Dock Hiding off in there. However, they can still click on the option area (the lines) in the dock and turn it back on there. I know it doesn't seem like too big a deal, but when the older kids do this and a 1st grader sits down, they get confused and have to ask for help. If a dozen ask for help, it wastes time in class.

So is there a way to disable the ability to have that option available? I'd actually like to get rid of of the Hide, Magnification, and Position options in that little menu.