I put a bit of water in to and shake it so it comes out easy.

A few years ago I designed an adapter, but then my 3D printer died and I never bothered.

that's not dull enough. Take it outside, tech boy.

It took a few decades of thinking about it before I finally acted on it.

In use the tube points down into the new bottle.

It does not have a hole, but the tube is pretty wide.

I had thought about providing a way for air to pass into the upper bottle, but I decided it probably isn't necessary.

My expectation is that the shampoo is thick enough to cling to the inside of the tube as it drains down, and thin enough to leave space for air to pass up through the center of the tube.

It's getting it's first use today. I'll leave the old bottle draining into the new one until tomorrow morning, so even if it has to do the glug-glug thing, it should still successfully drain completely.

Just cut it off diagonally, that way the hole can't get blocked by the sides of the bottle.

I was worried that this would be too exciting to qualify, but then I told my wife about it, and used her reaction as a guide.

You need to get out your pocket knife and epoxy and free yourself.

It's like a weight has been lifted off me.

The knife is for the pump edits. I'm not recommending self-harm.