If only tootpaste can be refilled, what a better environment we would have. So I make sure nothing is left inside by squeezing it as hard as I can using my toothbrush handle.

This is my toothpaste after several squeezing.  It's totally flat to reduce frequency of buying. I also practice trying all available toothpaste to find out which is the best for me, meaning, no need to brush more often to avoid bad breath.