Summary

This is a different implementation of the idea I had had seven years ago.
A smaller, lighter round dish instead of a large square basin , with a different locking mechanism and support for the refill bottle.

This thing is supposed to be used on 1/2" (12.5-13mm) pole/stick.
The key is better to be printed leaned slightly - to make the layers placed diagonally, but not necessary. You may use a paper binder clip instead of a key - just to pinch the slit walls together, should be enough to hold the dish on the pole.

Bottle holder brackets need rubber rings.