That magnet trick is pure gold. Used the same method on a brick wall last fall to find the old steel nailing strips behind the plaster before drilling. Saved myself from hitting a pipe for sure. My old boss called it "seeing through walls for five bucks." Those little field tricks from mentors are the best.

Old school hand tension worked fine for me.

Saw the same thing on a river job near Mobile... they swapped to a ten-inch suction and it was like night and day.

Man, I used to be totally cool with it. Then I saw how it actually works behind the scenes one time, the whole process. Completely changed my view, now it bugs me too.

Actually, @the_mia, some parrot trainers use quiet cues with treats, right? Could that trick work for a film set?