Subject: OXIDATION OF STEEL WOOL-SALT WATER vs. TAP WATER?

I AM CONDUCTING AN EXPERIMENT WITH MY SON TO SEE WHEN STEEL WOOL 
 WILL RUST THE QUICKEST. THE EXPERIMENT IS AS FOLLOWS:5 JARS     
 JAR 1:STEEL WOOL EXPOSED TO AIR JAR, 2:STEEL WOOL HALF FILLED 
WITH TAP WATER EXPOSED TO AIR, JAR 3:STEEL WOOL FILLED WITH 
BOILED WATER AND CAPPED, JAR 4:STEEL WOOL,DAMP CLOTH EXPOSED TO 
AIR, JAR 5: STEEL WOOL FILLED WITH TAP WATER AND A PINCH OF NaCl 
 exposed to air.  OUR HYPOTHOSES WAS THAT THE STELL WOOL IN THE 
SALT WATER WOULD RUST THE FASTEST BUT THE STEEL WOOL IN JAR 2 
SEEMS TO HAVE RUSTED THE QUICKEST.WHY? IS IT BECAUSE THE NaCl is 
slowing the oxidation process by forming stronger bonds with the 
water molecules thus slowing the rust formation?    THANK YOU 

Re: OXIDATION OF STEEL WOOL-SALT WATER vs. TAP WATER?