I have used a 10 inch tubular screen that screws into the backside of my ball valve inside of my boil pot. When I open the valve, the hops inside act as a filter and the wort runs clean… very clean…BUT… very slow… TOO SLOW. With the extended time your wort is exposed to the outside air, you run risks. I have given it a shot, but the clear wort into my carboy isn’t worth the extended time and risk of infection.
Personally, I whirlpool for 15 minutes… and use a pickup tube to pull wort from the outside edge of the kettle… avoiding the middle. Then when I open my ball valve I don’t crank it wide open, I go steady.
The filter idea you talked about MAY work for some beer styles (Non super hoppy) or your brewing methods (Using a hop spider or muslin bags etc) but mostly hop material is going to clog them and you will have your work cut out for you when it stops flowing through the bag.
You, like many others have searched for the single answer to this creature called Trub, but using screens, filters, bags, wirlpooling, better brewing practices, etc is all part of eliminating trub and hop matter. I just give it my best and accept what ends up in my carboy. COLD CRASHING is the best thing for me to help drop out anything I don’t catch and knock down any hop matter that’s still floating around.
Another good method that’s even practiced by commercial breweries is whirlpooling with a pump. The pimp is hooked up to the boil kettle in two places. Wort is pulled from one location and pushed back into the kettle (Either at an angle or a special fitting) and ran that way for an allotted amount of time.
As a home brewer, you can accomplish this with a pump or just use an attachment for your drill. Some use paint mixer attachements, I use a plastic paddle that fits into my 1/2 inch Dewalt drill. While whirlpooling, you will have your immersion chiller pumping water while your whirlpool is forcing matter to the center of the pot AND your moving a lot of surface area of wort around the coil (Assuming you don’t have a plate chiller).
ANYWAYS, as you can see, a lot of things go into fighting trub and hop matter. As a home brewer without commercial equipment, I believe that better practices from the beginning to end of your brewday will help produce a clear beer.