Another thing I have done a few times....when alot of meal gets int he grease you can cook some fried chicken in the grease. The flour takes the drippings (meal) to the bottom and cleans the grease. You might barely taste a hint of fish but the chicken is still good. Main thing is it's cleaning your grease. As far as potatoes, I always fry french fries after cooking the fish. Then the hushpuppies all in the same grease.
When you're pouring your grease up just leave a little in the bottom of the cooker and that's where most of the meal is at. Unless you burn your grease you can just add more as the pot gets low and just keep right on using it for a long time.
Health nuts are going to feel stupid someday, lying in hospitals dying of nothing.