I spent some time working for a mob that manufactured perforated filtration screens from thin gauge stainless steel. As part of the process the screens where covered in grease. That meant after the screens came off the lasers they had to have the grease removed before they could be inspected. We used a high temp (120 C) high pressure washer to clean the screens and it did a brilliant job of getting rid of the grease and the adhesive that was used to bond the stainless to the polycarbonate backing sheets. The pressure washer did a few foreign orders over the years cleaning dusty and greasy rally car parts and it worked a treat. The hotter the water the better. I am wondering if you couldn't replicate this buy using one of those cheap pressure washers from Supercheap with a hose connected to the hot water outlet in the laundry.
For surface rust wire wheels or if your keen the combo brushes from Suhner or 3M where quite good for removing surface rust from mild steel sheet. Only draw back is they leave a brushed look to the surface once done. The surface needs to be dry and free of grease otherwise you will destroy brushes rapidly.

One of the methods I plan to try when I go to clean interior bits in the van is using a diluted (by water) mix of wax and grease remover and imersing them in tray of this mix overnight. Quick blast with the hose or pressure washer when they come out. Unsure how the plastic trim will react to the prolonged exposure to the wax and grease remover so I will exeriment with damaged parts first!

Anthony