چدن روی گاز من چربی ضخیم و کهنه گرفته چطوری تمیزش کنم؟

I don't know. The provided context does not include specific information on cleaning thick, old grease from cast iron parts of a gas stove. The available articles focus on topics like vacuum cleaner filters, gas cooler cleaning, or appliance error codes, but none address this exact task.