A: I wouldn't blow down any barrel

B: I wouldn't swab a barrel with undiluted alcohol, ISO or otherwise

C: "Flash point" is the temperature where vapors can be ignited with an open flame (motor oil has one, too)

D: Rain-X washer solvent contains a polymer in solution; when the solvent is evaporated, the polymer is precipitated on the vehicles glass (or paint, etc) so I wouldn't be inclined to use it, either.

E: If cost is the factor in using an alternative to Hoppes #9 or similar product, what's the matter with boiling water and soap?