Started using Hoppe's 9 when I was given my first .22 rifle a bit north of 70 years ago. One Hoppes product that beats 9 is their Benchrest, which works a bit better on copper. It is as safe as #9 but requires soaking overnight for several days on the stubborn jobs. A dozen or so years ago, I started experimenting w/some newer, more efficient solvents (some of which are shown behind the winner, none of which has the satisfying odor of old #9):
View attachment 877477
Speaking of the (wonderful) smell of older Hoppe's 9 and the Hoppe's air freshener, after burying my pickup to the floor boards in some S. Tx clay and collecting an inch of water on the floor mats, my wife complained that my truck smelled like a wet puppy every time she rode in it.
The Hoppe's air freshener became a rather uplifting additive to my truck. I now refresh it with (new) Hoppes from the loading room regularly, but sure wish I'd have stashed a bottle or three of the old Hoppes for that duty.
View attachment 877478
Regards,
hps