We are new to owning an older Airstream (1971) and were looking for a product to remove the factory gel coat that was not so abrasive to the environment and ourselves. We chose Citris Strip that we picked up from Home Depot and Lowe's and it worked out well. You just paint it on and remove with a hose with a good nozzle. It might take a couple of applications for tough parts but we didn't mind as we had dogs in the area we were stripping the trailer and didn't want to poison everyone with harsh paint removers. Here is a link to our blog
which includes exterior and interior work.