The question is: Is there a thorough and safe method to remove fly maggots (a lot!) from the soil of an area where there are precious plants growing?

Very long story short: I haven't been out in my tiny yard all week except briefly very late when I come home at ~11pm to call my cats in or the like. Today is my "Saturday" and I was going to catch up on chores. Last weekend I found that a young stray had moved her 2 kittens into the neighbor's weed-choked lot, just under the chain link fence from the corner of my garden (she herself was born there last summer). Probably because I poked around and looked, she moved them away from the fence and I didn't see her the rest of the week.
Today I found the remains of her body under my tomato plants. Remains meaning fur and bones and soil teaming with maggots. Not sure how long that took. :~P The remains were removed as best I could as it started to pour, the 2 kittens were located and rescued from under a board in the alleyway behind my yard. But there is no way to eradicate all those fly maggots that I know of.

I took a gamble on mixing organic insecticidal soap into my watering can and using it as a soil drench but it really doesn't seem to have done much, at least yet...it may not. The little bastards are now spreading out, climbing the edging wall, wriggling all over the place. Without digging out my tomatoes, the herbs around them, and tons of good soil, I cannot think of a way to remove them. Given my hunting cats and the volume of strays in the adjoining alley, birds are wary of the area. Any other ideas??

BTW there are 2 adorable fluffy fleabags now tucked in a carrier in my living room and being hand-fed. If you want a kitten, these ones are sure survivors!

Sending good wishes your way,

Sparkle