The cups looks great, but won't work in our climate...too cold in winter.
For our chicks, they all had the nipple waterer figured out within 2 hours. I started them on the nipples around 2-3 weeks of age, though I'm sure you could start sooner. The first chick figured it out in under 15 minutes and the others followed in less than 2 hours. I removed all other sources of water. Thirst drove their desire to find water. If you leave them an easier/known source, they will likely ignore the nipples.
For our grown birds, it took a bit longer. When I first hung the nipple bucket, they pretty much ignored it for the first couple hours. Then when one of the chickens was near it, I flicked one of the nipples in front of her and I saw that she saw the water drip from it. I did this several times and each time it garnered more interest from this bird, she kept going to where the water was dripping onto the ground litter. This was after a couple hours, so I know she was thirsty (it was a warm day 85F or so). I set up a video camera aimed at the bucket and left for 3 hours while it recorded. When I reviewed the video, the first bird to figure out the nipples was the one I had shown it to and she figured it out about 30 minutes after that. Within a few hours, most of the birds had figured it out. They seem to learn from watching the others. There was a couple birds that I hadn't yet seen using the nipples, but that doesn't mean that hadn't figured it out. They acted and appeared fine...no sluggishness or signs of dehydration. I had removed other sources of water except for the small pond that was about 150 yards away. They usually only drank from the pond in the morning, so for two mornings in a row, I kept them shut in the coop/run with the nipple bucket as their only option for water until after noon. I verified all but one on the first day of the shut-in and the last one on the second day. To summarize what I did:
day 1: hung the bucket, flicked a nipple in front of a bird, let them free range, verified most birds use the nipples
day 2: shut them in for half the day, verified all but one bird using the nipples
day 3: same as day 2 and verified the last bird