I recently acquired a rather used attachment for my FEL (free) that has what appears to be a light rust/corrosion inside the steel tubes near the end fittings. Is there any easy way to adequately clean this or are these tubes trashed and have to be replaced. I was wondering if they could be flushed with some type of solvent thoroughly then put them back in service. Maybe run a wire brush through the tubes like cleaning a rifle barrel. Any ideas? Should I put an inline filter on the output for a while to prevent any particulate from returning to the sump and the rest of the tractor?