Help in anzalyzing science project results!!!?

ok i did my SFP on bio rusting i took 4 jars with distilled water and put two rust nails in each. all the nails are sanded for no protection from bacteria and i put antibacterial soap in four of those jars. I took another 4 jars and put a large amount of dirt into them with also two nails in each. I also had another jar that was the control. only filled with distilled water and just two nails (all the nails are sanded*) the results were the control nails had rusted the most. the ones in the dirt less and the antibacterial ones like more than the bacterial ones .. these results confuse me do you think there is some type of error in this procedure or should i have another trial and test with something other than dirt, and something other than antibacterial soap..?