I use a homemade version up at our camp. The neighbor's don't have pets, they have cows. I use a maison jar with a piece of raw meat and a little water. A funnel fits in the mouth of the jar. The flies crawl in and can't get back out. I keep it a little distance from the porch because it does start smelling ripe.

I have a huge fly problem, too. I heard that running a fan will keep the flies away. I'm going to try that next spring to see how it works.

I'm also going to purchase fly eliminators. I plan on purchasing from this website: https://www.arbico-organics.com/category/fly-control-program.  I haven't tried it yet and don't personally know anybody who has, but if it eliminates the flies, it's well worth it. Will be trying the monthly subscription starting next spring. I'll report back here with my results in case anybody is curious.

I also purchased fly traps from Amazon: https://www.amazon.com/gp/product/B07J1TZLHL/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1.  I used these this past summer and it was amazing. Definitely noticed a big decrease in the flies, but not a complete elimination. But I also didn't put them out at the beginning of the breeding season. I plan to use it again once the weather warms up.

Between all 3 methods, I hope to have a fly free patio!