I recommend you get a belt designed for weightlifting if you are lifting weights.
Is this a serious question?
I've seen strongmen wearing an extra wide neoprene belt, looks more like a corset, under a normal width lifting belt. I think a few companies make them and they do look very wide like the ones in the link posted. I think they are also designed more for keeping the lower back area warm but if you are doing a 20 rep squat mission won't you be warm enough before the event?
Please post video if you do this.
I have a belt designed for weightlifting, that isn't the problem. I was thinking about it to keep my lumbar warm, worn under my weightlifting belt. I don't know what you'd get out of a video, morbidlyfat. It'd be a pretty normal 20rep squat set, you would likely not even see the neoprene belt.
After a little more research, it looks like b17vic is correct, there are more than a few strongman competitors who do this. In fact, this is popular enough that Rehband now makes A back support that combines the two.
http://www.jackalsgym.com/store.aspx?prod_id=RH-SM-BELT