"Trolling" :)

has anyone used bottom bouncers?

I do, they get hung up a lot in Arthur.  They work if the fish are at the bottom and don't run into a hump.  You can experiment with how much line to let out and size bouncer & speed to get you somewhere near where you want to be, but not the best tool for that (unless a lot of time to experiment or just get lucky).  There was a different trolling thread going around a few weeks ago that talked about using dypsies and other trolling weights.  I actually thought it was this thread...  Just noticing this is one from 2014.  Those humps seem to grab a hold of any trolling weight.  Much cheaper to loose a bottom bouncer than dypsy.

As I think someone noted on the other thread, or could have been another site...  Find a nice stretch of flat bottom.  Run your bottom bouncer, just so that it is ticking off of the bottom.  Note how fast, how much line out and depth of water.  You can use that as a reference point.  
 
So, if you find 20 feet of flat bottom, and you are ticking bottom at 2mph and 60' of line out, you can get a rough estimate.  Every 30' of line you let out will get you down 10 feet if you keep that same speed (if same size weight and same lure being pulled behind it).  Most likely, you aren't going to find numbers that divide so easily, and it isn't going to be a true rectangle to figure out depths.  If you ever check out lure trolling charts, they are a bit of a curve on depths.  Like said, a general guide.  If running multiple rods, then put them at different depths and go with the one that works!