Is there an easy but effective way to clean the oven?
Here is the easiest way: Pour 1/2 cup ammonia into a glass bowl. Place the bowl in a cool oven and close the oven door. Leave the bowl in the oven overnight to let the ammonia fumes do their work. Wipe clean the next day with paper towels or a sponge. Rub tougher spots gently with 000 or 0000 steel wool. Rinse the residue with warm, sudsy water. Repeat steps if necessary- but it seldom is necessary.
Oven Pride from any supermarket. Its the best one I have used. You put all your racks into the plastic bag they supply and then pour in enough liquid to coat them, leave them for several hours, I have left mine overnight before, then you can use the rest of the liquid to clean the inside of the oven, you may need a couple of goes for the roof, but it works. Beware though you must wear gloves. When you take the shelves out of the bag, just wipe them over with a cloth and water and they will shine. I haven’t found anything better.