Arbico Organics has a solar fly trap that is $90 or so but is reusable year to year. I have tried the fly larvae eater but it is hard to keep up with. The solar fly catcher uses a yeast bait with whipped egg and carbonated beverage. All non toxic. It works and will buy a second next year.
Also I take the pop up reusable fly trap and mix an egg , two tablespoons of proven yeast, carbonated beverage and one of their baits and make a gallon which I add a little to the trap once a day. Anything that stinks like old milk etc brings them in
