If I go by my shopping list when I used the organic soil without gloves then I've had my infection since late summer/autumn of 2011 and only reached major symptoms around Dec of 2013.
DE works on the big ones by cutting them up. I don't think it does anything to the eggs so! you can get rid of the big ones over time by gradually increasing your doses of DE but you will still have the eggs to contend which will grow into more big ones.
If you have Ascaris I think that meds are the only way to go and even that hasn't worked to kill mine.