Mine cover two burners so they are large.
I put them in the dishwasher--works well.
I wipe mine down each time I cook to prevent build up. Mine are very heavy so I don't want to lug them on & off all the time. If there is some kind of build up, I take a steel wool scrubby to clean the area. If they are very bad, you can remove and clean with oven cleaner (commercial or DIY).
Perhaps this will help, Linda. https://products.geappliances.com/appliance/gea-support-search-content?contentId=17275
Hi Linda: What I use is a paste of vinegar and cream of tartar (the dry stuff). Make a paste and put it on the gunk. Let it sit for about 15 or 20 seconds and then scrape off with a plastic putty knife or one of those plastic scrubbies. You may have to do it a couple of times if the gunk is thick, but usually not. There is no smell and it is environmentally safe and if you don't get it all off, no harm, just tastes awful:) Good luck.
vinegar and baking soda