Sandblasting is fine as long as it's in high crown areas or areas with lots of detail like door jambs, tailgate area, etc. That's how I did mine. I even blasted the beads in the roof because it's hard to clean them any other way. I blasted pretty much all of the interior as long as it wasn't the backside of exterior sheetmetal. Use fine sand and as low pressure as possible while still cutting the rust.