How hard is it to find the " studs" (ties) in an IDF wall. Thinking here that i migth not be able to use a " stud finder " as in a regular wall.

Stud finder does work

Also start in the corner and measure out 6" or 8" depending on your block and good chance you will hit a stud as well unless of course you have a stack joint that you passed

Neither of my stud finders work. I got a tip from others on this forum to use a small magnet to find the drywall screws. That approach has never failed me. It might take a few minutes to find the first one but once you do you can easily measure all the way across the wall.

As Chris says, you can be tricked with stacked bonds that, in my usual installation method, would most likely occur under a window. Since I often use glue instead of screws, there is one place for sure that you will certainly find screws and that is where the drywall edges meet. At 48 or 54" from the ceiling (depending on wall height), there will be a horizontal line of paired screws. Once you find one, you're off to the races.