For at home cleaning I used aircraft stripper and a pressure washer. The stripper is good on baked grease/grime not to mention old paint. Goop it up, let it sit for a half hour or so and blast it. It took two rounds to get mine completely clean.

For coating, I like paint. It is thinner and holds a tight bolted joint better plus easier to touch up.

On mine, I sanded loose rust then hit it with Eastwood black rust encapsulator then SG black all in spray bomb. It has held up great.

I got all the above done outside in one breezy warm summer day.

After several years I had new ends installed. It was a quick job to clean it again with detergent, spot prime the new metal then shoot the whole thing again with SG black. That also has held up well.