Cleaning steering box?

Depends on the nasty, corroded and pitted or just greasy? How greasy it is? Use some solvent or a pressure washer if grease is really thick. Castrol super clean and a solvent tank brush for final clean.

Get the grease off and see what’s there.

Forget all the abrasives, sand, wire brush/wheel, etc unless it is corroded and rusted on the steel parts.