Replenish knows something that you might not—almost all (they claim 95%) of cleaning agents are water. The rest is the chemical concentrate that gets things done. So why pay for water? Replenish sells empty bottles and concentrate. Simple.
When the bottle arrives, you just fill it up with your own tap water and pop on an included concentrate pod. The mixture gives you what you would have purchased off a store shelf, without any of the senselessness of paying for what’s essentially a bottle of tap water. A Replenish spray bottle costs $8, and comes with enough pellets for four fillings—extra cleaning pods are $4 each. Yes, you’ll have to do a little bit more—ack!—work to mix the stuff together, but you’re saving both money and a tiny piece of the environment by conserving materials. Why didn’t someone think of this sooner?
Taken from here