Take a small ball of steel wool (say 20 grammes), enough to comfortably fit inside your bowl ... then take the battery and your hand away. To get the reaction really going, try blowing gently ...

If you need to remove tree sap, adhesive residue or other hard to remove stains from your windows, try #0000 (4 ought) steel wool. Lubricate the glass with a spritz of window cleaner (Windex ...