I just installed the push-in nipples from farmtek 2 days ago.
I did my other halfs pens first. He has pheasants, turkeys, and RIR chicks.
I did not use any glue at all. I drilled a 3/8" hole and put in grommet and then pushed in the nipple. Now the first one leaked.. hummmm went back and took it apart and found that there was some plastic left from drilling out the milk jug. So I trimmed that and woohoo a nice waterer. The turkeys and chicks jumped on it right away. The pheasants weren't too sure.
I talked to a rep from Farmtek (by the way the customer services is beyond belief) they told me to remove the pan then take water and pour down over the milk jug.. as the water rolls down it will find the nipple and run off. They said a bird can not resist running water. They were right.. I stepped away from their pen and they came and pecked at the water all around the jug. then one spotted the water on the end of the nipple.. and hit it.. after that they were all their to investigate.
They did tell me that if you want to use them without water pressure to get the ones that are threaded instead of the push in. That they work better as a gravity fed watering system. They are the same price. At this point I see no problem with the push-in so I think when I order for my silkies I will get some of both.
I only bought 5 to try as I never thought about searching here for someone who may be using them. But as of this morning all I have install loves them. Now I had one left for me.. well I kept one for me. Other half thought his birds were more important to start with... so to prevent and agrument I installed in a few of his pens first. I have the Durafonts (3, 5, and 7 gallon) for my chickens but they scratch woodchips and dust into the pans even when up on milk crates. So I have put one of these nipples in the bottom. I have a plug for when I want to clean it and have it hold water to do that.
I when I reorder will get a few more and put a couple in each one I have. maybe the screw in ones they are self taping so will fit nicely. I took those hooks that screw into your garage to hold your bicycle and put in the side of my coop and hung the waterer. now no dirty/dusty pan and more floor space. They love it. I was really afraid to put a hole in one as they are $50+ a pop and was afraid it would ruin it. But woohoo a really nice waterer and they love it. Now winter we go back to the rubber pans that I can get the ice out.
I will say farmtek also said the screw in ones are easier to remove to clean or exchange the container than the push in ones. the one that leaked due to my error was not hard to remove but the grommet comes out with it and its a #%$%$ to get off there.
Hope that help..