I have used all sorts of degreasers, dawn and soaps...I am sure a steamer would work GREAT too, but at $800+, not everyone has that. I use WD-40...I use a old rag and spray the WD-40 on the rag...it cuts right through the grease; then wash the jamb with regular car wash shampoo. WD-40 originally was a degreaser, cleaning agent.