I can usually get them to hatch, just bung them in a bottle of salt water on a warm sunny windowsill.
Keeping them alive is slightly trickier, I struggle with the balance between no algae growing, so they have no food, and so much growing that the tank turns into green gloop and the shrimps all die ... I've had most success with them in a small fish tank with gentle aeration; and changing 2/3 of the water whenever it got too green. That colony lasted about 6 months.
We used to have same problem, but at home with my kids no issues & we kept them for well over a year.
Think maybe we overthink things in schools & try to do it all by the book as it were.
We used bottled water at home.
Pupils here used to ask if I was just giving them pile of dust to save money!