I found the scrubbing and oven cleaner to be a lot of work. So, i set up an electrolysis bath. Much easier and well worth it if you are going to do many pieces, especially if they are in bad shape.
Rubbermaid container with cooling rack in bottom, wire attached.
Rubber sink mats next.
Griddle with wire attached. Using a 10 amp battery charger.
All the yuck coming off.
Super easy. The only part that costs much money is the charger, if you don't already have one. I paid $35 for this one.