Hob - cast iron pan supports - clean??

[oooggs]

My double oven is a complete state!!!!! I was going with oven pride and starting with the bits I can see Struggling getting the pan suppoets clean

How do you do it???

I put two of them in oven pride but has come up that fantastic. I am trying a wire brush

If the fade can I paint them with coal paint???

Sorry lots of boring questions