I have another problem and this is with the LIXIT 5/8 nozzle. I just got that bottle mounted last night and this morning I found the water half gone and the papers beneath were saturated with water. I took my cockatoo out of the cage replaced the paper with dry paper and waited. The papers are wet again. No matter how I try to position the ball, tap the ball with my finger it does not stop the drip. Eventually, it returns.
It is rare that the nozzles will leak that much.
There are a few reasons and some can be corrected.
If the nozzle is not seated in the bottle correctly it will leak.
If the nozzle is up too high or too low in the stopper it may leak so check that.
If the water when put in the bottle is very cold, it may leak until the water reaches room temperature so always use room temp water. It is normal for a few drops, teaspoons or so to leak in the morning due to the temperature changes during the night and the warming back up during the day.
If the rubber stopper has a crack in it or has shrunk from being washed too much in a hot dishwasher or left out in the air unused for a LONG time, it could leak.
If there is a seed stuck up in the nozzle it can happen as well.
If the cockatoo has bent the nozzle so it is not round, the ball cannot stop the water. There is another nozzle in the 5/8″ thickness called a TUFF TIP that has a reinforced ring at the opening to stop this with the destructive birds.
Once all these suggestions have been ruled out then indeed we can have another nozzle and stopper sent out to you.
As far as the brush needed to clean the nozzle, I have found the thinnest aquarium brushes do work very well and have used them myself.