Yes you can. I poured it down the spark plug holes on my tractor to free up the engine, I left it alone for 5 days. The product is biodegradable as well.
can this remove rust from tile
Yes, this product can be used to remove rust from behind a mirror.
Absolutely, I washed the parts with soap and hot water (so it evaporates quick) then prepped with acetone to remove oils or dirt. Then I coated with self etching primer, sanding and tacking between coats. Allow primer time to dry then sand, tack and spray your color coat. It's all normal painting techniques for bare metal. It will flash rust after washing depending on humidity but that cleans up with scotch brite pads.