In a few old books I've seen reference to Dr. Hudson's nitro solvent. I decided to make up a mixture myself. Getting sperm oil not being a possibility these days I substituted it with jojoba oil. I must say it does do a good job at cleaning out smokeless (nitro) powder fouling in my barrels - both with lead and jacketed bullets (although in the latter case it just removes carbon fouling and not the copper). As much as I love the smell of Hoppes #9, a few other members of my household do not for some odd reason. Dr Hudson's formula does have a nice odor but is much less pungent so I guess it helps in that regard too.

Cheers,
Dave

Sounds basically like Ed’s Red. Dextrin ATF has frequently been used as a substitute for sperm oil. Formula is equal parts Dextron, turpentine, mineral spirits and acetone. I used it years ago until I started cleaning exclusively with Kroil. 

My new bore cleaning system. I find it makes the mundane chore of cleaning barrels almost enjoyable.