Air spade

The Air Spade excavates dirt with a powerful stream of air. I'm not sure how well this would work here in the Rocky Mountain dirt, but the concept is interesting. The product is marketed as achieving a stream of "Mach 2" compressed air, by virtue of a special nozzle (here's the patent). This tool is over $2,000 on Amazon, and the heart of it, the nozzle, is available for $430, but I'm wondering how much of this can be achieved with a correctly made nozzle.

https://www.youtube.com/watch?v=AbbxFqHaCTk

More: https://www.airspade.com