I have a performer blue with the plastic table I picked up recently, and the lid and bowl shined up nicely with 0000 Steel wool and water with dish soap as a lubricant and light degreaser. The plastic table was pretty badly stained brown, and a soft brush and dish soap wouldn't get it clean, so I used Bar Keeper's friend. This stuff works like a dream on the kitchen stove at removing burned on spills, and worked awesome on the plastic table. Be careful though, this stuff has a mild acid in it. It works wonders on breaking up surface rust, stains, and discoloration on stainless pots and pans. Put the powder on a slightly wet surface and scrub it in a little. Let it stand for 30 seconds to a minute and rinse off.
Not sure how it would fare on the Kettle finish, but it doesn't ruin the cheap finish on my kitchen stove. (white)