Anybody Tried a Milwaukee Airsnake?

I've generally been impressed with Milwaukee, but I agree with your concerns. The bladder (receiver) within that tool can't be that large so you're only getting however much volume of gas through the line that 50 psig expanding to 0 psig will get you. For more sensitive (weaker) piping systems, you get even less. I believe them when they say they've cleared lines over that distance, but if I were them doing the test I would pick the most easy clog to clear in order to make that statement. So, it's a nice tool under certain circumstances.

Interesting idea. Is there a reason you couldn’t just use an air compressor for this type of thing?

I’d be concerned really all you are doing is blowing a small hole in the clog. An auger somewhat does the same but much of the time you grab something and pull it out.