The best way is to send it to the radiator shop. They can boil it out and reline it. That also the most expensive way.
The cheapest way is to remove the sediment bowl, throw it away, then stick the power washer in there and blast it out. I then run lots of water till it comes out clear. Let is sit for a couple days to dry out.
I then install the assembly pictured.
It works perfect!
It's full 3/8" brass pipe that will not plug up. Any big pieces end up in the bottom and can be easily cleaned out by removing the cap.
Filter stays clean and so far I've never had one plug up. I do replace them yearly when I change oil. I have 6 tractors with this set up.