you dont mail them back all at once, you collect them and send them back in the envelopes they provide.
they are very, very light.
mail trucks go from my community mailbox to the city centre, then to the other hub whether or not my few ounces of brush heads are in there.
Nothing is perfect. Take biodegradable trash bags for example. There’s a higher carbon cost to make those than thin petro-chemical regular bags. You need to weigh up landfill waste vs energy costs with everything, but with more energy. Same with mining for lithium for EV batteries.
Nothing is perfect. This, I believe, is a better choice.
ok but its really nothing like salted caramel…
that salmiak is ammonium chrloride, not sodium chloride which is whats in salted caramel… and salted caramel is balanced between salty and sweet. I’ve had sweedish salmiak candy that is essentially a hollow cylinder of licorice that melts to a point that it dumps a quarter teaspoon of ammonium salt onto your tongue. no salted caramel comes anywhere near that, and for gods sake why would it