The use of a hole saw is the problem I see too. You could use a plunger to drill into! That would work. lol. Once you got your pilot hole you would know where to put it. Then finish the hole, and quickly remove plunger and install the jet, put the valve on it and close it.

I would say that two people would be getting wet though in the process. Can't be any worse than fixing a watermain break. And at least it is warm outside. LOL. I say let them do it, film it if you can and put it on YouTube.