The basket occasionally went in the dishwasher which cleaned the surface, but the well gunked grease has been building up.
Tried soaking the basket in soap and hot water. Scrubbing with a soft sponge. And then running the dishwasher multiple times but it only got a small part of the grease out.
Maybe a good soak in vinegar, then alcohol
Most of what I know about grease comes from industrial machinery. Maybe it doesn’t transfer over well. Steam is also a good option.
When fats get to high enough temperature they polymerize, on cast iron we call it seasoning. If you let the grease build up, and go through many cooking cycles your actually trying to get rid of polymers