C.K.
Run the washing machine empty with detergent and bleach in it. If there is grease in it, add some Simple Green (about 1 cup). That is what I did when my husband worked in the oilfield and I had to wash his filthy clothes.
Simple Green works wonders. Add it to the wash next time his rags need to be cleaned and the grease washes out and doesn't stick to the washing machine. I always washed in cold water and the Simple Green still got the clothes clean.