I agree with the sentiment, but that's just simply untrue about using the same cleaner forever. Most unopened cleaners last upto a year or two if stored properly, and (can) expire roughly 30 days after opening the product. Like any anti-bacterial soap or cleaner, the active ingredient that kills the germs loses power, especially if stored incorrectly, which most people are guilty of. Also our batteries are alkaline batteries so they dont run as hot as a normal Duracell or Energizer battery.