I use a combination of baskets and bio-gold. The baskets are good if you want to control timing as you can remove them and the fert is gone. With the bio-gold it's difficult to remove. Also the bio-gold can make a mess on the soil surface so sometimes I don't want that. Yes the fert will kill moss around any type of fert, but it's usually pretty localized. I use the Portland Rose society fertilizer pellets in my baskets. Never had any problems. The mold you may see is part of the breakdown of organic ingredients. I've never seen maggots!