Have you tried asking the supplier what it suggests? The paint stripper must be ingrained into the wood. Most are water-soluble, so scrubbing with water might do the trick. And/or try a primer coat of aluminium primer first.
Hi okladene
Don't know if this is too late, but anyway - try rubbing some linseed oil into the door and letting it dry then re-painting.
Good luck
FBG40