I've been neglecting cleaning the drip pans on my gas stove-top for some time (as you can see by the first photo). They had gotten so bad that I priced new drip pans (way too expensive to just replace) and decided to check the internet for cleaning ideas or tips:
WD-40: did get the top layer of grime off, but not the really dark stuff underneath
oven cleaner: seemed a little harsh outside of the oven
boiling and scrubbing with baking powder: took a lot of time and only did an ok job
So, I decided to try my own methed. I rubbed Dawn Dish Detergent into the stains and poured hot water into the pans and let them set for about 15 minutes. Then I got out the steel wool and wiped away most of the grime. I had to scrub a little harder on the really bad ones, but they came out looking like new!!