Review (5/5): Works well, needs a little modification to simplify your end
This is super easy to make. When it cools it is just a bottle of liquid conditioner. Honestly it took too long for someone to come up with this
I made it right in a plastic bottle. I tested the bottle with boiling water first to make sure it would handle it. Then I cut the cubes with scissors (cuts pretty easy) into smaller bits so that they fit in the bottle I wanted to reuse. That part was a little messy and I had to gather up all the bits with an index card but worth it to save the step.
Highly recommend