HYDROGEN PEROXIDE cleaning!
Whaaaaa? Turn AA batteries into C cells and D cells-- Just wrap some cardboard around the AA battery so it's the right diameter. Fasten w/ tape or rubber bands. New rechargeable AA batteries have plenty of power to run devices that used to require the bigger batteries.
Remove the cardboard tube and a roll of toilet paper becomes a box of tissues. No unraveling hassle! Okay this is smart!