I've been using the Lady Bug brand seed starter called "germinator". I've had amazing results with it, it's not sterile, though, but it hasn't been a problem and I'd say in my case it probably helped. I had lot of fuzzy mold growing over one batch that I used over 2 years, but I never had any damping off issues or other problems, the seedlings loved it and always grew nice and strong. So any mold in that mix was certainly a good mold or fungus. Some mold/fungus types are a sign of healthy soil (some form symbiotic relationships with a plant's root system), so if it ain't broke don't fix it
