Baked-on grease leaves a hard-to-remove residue on oven racks. The grease generally does not come off with regular cleaning. Once the grease has been baked onto the oven racks, it may take several attempts to completely remove it. But don't throw out the oven racks and buy new ones before trying some home methods to remove baked-on grease. You may be surprised at how clean your oven racks can get.
Line the bottom of your bathtub with an old sheet or towel. Place the greasy oven racks into the bathtub on top of the towel. The towel prevents the racks from scratching the bathtub.
Fill the tub with hot water. You only need enough water to cover the entire surface of the oven racks. Add ¼ cup of degreasing dishwasher soap while the water is filling the tub.
Let the racks soak for 1 hour. Scrub the oven racks with a scouring pad while they are still in the soapy water. You may need to scrub forcefully to remove all of the grease and grime. You can also soak the racks overnight. When you wake in the morning, most of the grease should be removed from the racks. A light scrubbing is all that will be necessary.
Add ½ cup white vinegar and ¾ cup dish washing soap for an alternative cleaning solution. Soak the racks in the bathtub filled with hot water and the cleaning solution for 2 hours. Scrub with a scouring pad and rinse clean.
Use oven cleaner as a last resort to clean the oven racks. Oven cleaner can be messy to work with and produce strong fumes, so only use this method if the others were ineffective. It is best to do this outdoors, if possible. If not, use your bathtub for easier cleanup. Lay down plastic garbage bags wherever you are working. Place newspaper on top of the garbage bags. Put the oven racks on the newspaper and spray them with the oven cleaner. Apply a thick coat to the racks and allow it to sit on them for about 5 minutes. The baked-on grease should begin to dissolve. Scrub the oven racks, if necessary, with a rag to remove the grease. Spray them clean with a garden hose or run them under the shower.