I would keep pumping diesel fuel through the crankcase. Get about 2 gals fill it up and then drain it into a clean pan. Use a trans funnel with a screen to fill it back up so you can keep track of the metal and flake. After that use an extremely cheap and thin oil. Fill it up, run it for 10 drain. Fill it up with fresh oil, run it again and drain. Change the oil filter every time.
The best way is to disassemble the entire motor and wash each part and clean every port.