Nipple waterer training

[MackChicks]

I'm not sure what else to try... We hung a 5 gallon waterer with 4 nipples yesterday. We removed all other water sources and showed our hens where the water comes from. 24 hrs later, they are still not drinking from it. I tried for 20 minutes to teach them but they were just pecking the water on the ground. I finally gave in and gave them a bowl in which they drank from for at least 10 minutes. Suggestions?

 

[IceAngel]

Does the nipple have a valve? Could you stick a toothpick or some foil in it to make one of them drip? Then put down a sieve underneath the drip so that the chickens aren't tempted to drink from the puddle on the ground.