From my experience of training assorted animals to do unnatural things, you have to remove all food & water sources other than the one you want them to inspect.
This needs to be done well in advance of the time it will be required to be in service.
Which means lots of 5P's. (Prior & proper preparation prevents P poor performance.)
If you leave it until the last minute you are more likely to fail.
So for your quail, on a warmer day, remove all other water & food & change the bedding so it is brand new with no spilt food to draw their attention away from the smell of the water in the tip of the new waterer.
If warmer days are not available then turn up the temperature of the warming pad or heat source you use to make it the same as a summer day.
Once they get thirsty, the brainiest one will smell the water & begin investigating.
Others will follow once they see the first one drinking but some will not try.
You will have to keep a close eye on them to be sure none are becoming dehydrated from not drinking.
You will need to separate out those that wont drink from the new waterer otherwise they will all go back to the old one.
Providing those that don't drink with another water source actually concretes their rejection of the new waterer, but if they don't drink from something they will die.
So it's a catch 22 situation. If most are drinking from the new source, then process those that wont drink before their health suffers.
For future batches of quail, always leave a few of the older ones to teach the new ones the ropes. Once the new ones know what is what, you can process the last of the older ones.
Chooks for example, will switch between waterers but there are always some that will only drink from one or the other.
I'm not sure about the psychology of quail as to whether they are happy to switch between drinker types on a regular basis.
But I suspect that once changed over to the new drinker it would probably be best to only have that type in their pen in future.
If you need to save power costs then only plug it in as required but always use it as their water source.
Good luck with your training!
