I ordered some of the horizontal nipples to try with our new flock. I have used the vertical in the past and had leaking issues at the nipple itself. With the horizontal nipples, we can't seem to stop them from leaking (slowly) at the point where they are inserted into the container. We've tried several different types of containers and keep having the same issue. Hubby is drilling a 3/8 inch hole which I believe is what the instructions said. What could we be doing wrong? After seeing so many reviews saying "no leaks", I am a little puzzled and frustrated. I really want this to work so we can avoid the mess of regular waterers.