I noticed that every time I ran out of conditioner there was still a lot left in the bottle. Solution an over engineered coupler to allow you to screw two bottle together and let collect all the leftover conditioner.

Both sides are threaded to match the bottle with one side having and added sleeve to make sure the conditioner drains into the bottle instead of leaking down the side.

A quick tip there are some nice springs in the pump mechanism if you snap the top off!