You are going to be hard pressed to find achemical to strip it. The orange smelling aerosol gun cleaner they sell at Wal-Martwill eat it but it will take forever. Chemicals could also damage the glass,seals and coatings.

Best bet would be to tape off the glass and knobs and use a media blaster setREAL low. Carefully clean up any other areas you had to tape off with 600 gritsand paper. I've used the one at my gunsmith's to take cerakote and duracoatoff of parkerized finishes with success. Potential problems will be getting themedia between the knob and the housing. If you start with too much pressure itwill be shiny silver real quick.

Easiest thing to do would be to clean it up with some 600 grit and Cerakote it black or dark gray. You have to use the air cure or duracoat. You don't want to bake a sealed scope,