Just had to give mine some attention, after 13 years. Long ago I used old sump oil, let it soak into brake pipes, then blathered with thick grease, finally I put small diameter split plastic flexible electrical pipe over the top. This was at the front, over the really exposed sections in the wheel arch worked well. I couldn't use the pipe at the rear, so decided to just try to keep them oiled and greased, until I had them replaced this year. I replaced them with copper pipes.
The pressed steel rear arms, were the only part of the car, which had not been properly rust treated at the factory, so I had them rust proofed earlier in the year at great expense. It was suggested to be an expensive two stage process of some sort. Red and then a black coating.
They made a great job of the pipe, but I wasn't all that convinced by their rust treatment. I'd told them the priority was those rear arms and on inspecting it when I got it home, they had only done the underside of the arms, not even removing the rear wheels to do it, so I had 'words' with them and got them to do the job properly.