Here is a great tip for tenants from our Property Management Department on cleaning oven racks.
Put a sheet of alfoil shiny side up in the laundry trough, add ½ a cup of Napisan or something similar, put all racks on top. Cover with boiling water and leave for ½ an hour or longer. Pull the racks out and all the built up grime should wipe off easily. There is a chemical reaction between the alfoil & Napisan, the alfoil goes grey & brittle.
