I have done it. it was pretty weird.
a family friend taught me and it did work. we had a previously unknown waterline break and cause a fountain about 10 feet from the foundation of our house. We had the line marked out before the City crew showed up. The city crews said the line was not where we marked it and dug up where it was on there map. they found nothing, then they tried where we marked it. The line was exactly in that place.
Why would they even need a map in that case? Just dig where it’s shooting up out of the ground.
to find the shutoff.