I have heard of a product called evaporust, but to fill a full tank will be stupidly expensive. I wonder if you use a different type or filter that is larger as a primary if it will help not plug up so fast.
I've had a similar issue with my Cat machine. I went the route of using a larger primary filter and it helped a lot in reducing the frequency of filter changes. Give it a shot!
The apple cider vinegar trick didn't work for me either. I've had success with using a rust remover called Metal Rescue. It's a bit pricey, but it saved me in the long run.
Consider looking into a fuel tank liner. It's a more permanent solution and can prevent rust from forming in the future. The initial cost is higher but worth it in the long run.