Okay, enough folks here on the board appear to use those sippy bottles, that I have to get a little advice for this one. Nothing I do seems to help.
Those blasted washers on the inside of the cap and spout for the bunny water sippies…is there any safe way to remove them so they don’t get catapulted across my kitchen? I use the 16 oz water bottles, and the washers inside them get screwed in so tight I am practically having to use a crowbar to remove them while washing out the bottle. Then to put them back in, it’s almost necessary to have a jackhammer handy.
How about you all? Short of smearing them with petroleum jelly (which of course I would not) or cooking oil (ditto), I just can’t figure out a good way to get those things in or out of their seats without going almost nuclear in the process! Currently I have to force them out with a fork tine, which is eventually going to rip one of them into pieces, and to put them back in I seat them as well as I can with my fingers, then I screw the top on and use the bottle itself to push the washer down the rest of the way. The one day this didn’t work, I hung a full water bottle on Pip’s cage while we went to town, and when we returned a few hours later, she was swimming in the soup on her cage floor. Poor thing. 
Oddly, I don’t have this problem with the smaller ounce bottles (used mostly for Fiver since he’s a tiny) but those don’t hold enough liquid for Mimzy or Pip.