How to quieten a squeaky handle

Take the handle off the door

Just take this part off of the door (only one at a time). Put it somewhere that's easy to clean-up

Squirt the lubricant into the turning parts of the handle

Be generous. And then start using the handle, while still in the sink. This way you are spreading the lubricant around and any drips are not running down your door.

I also put some here for good measure.