IMO, you can use any oil you choose but I would advise you to just wet a dry patch and run it down the bore several times, rotating it between rams to make sure it evenly coats just the bore.
You really don't need much (if any) oil in the flame channel that connects the bore with the nipple.
Before you shoot the gun next time, run several dry (or alcohol (denatured) soaked patches) down the bore to wipe out as much oil as you can. If you use the alcohol soaked patches, follow them with a dry patch or two to remove the wetness before loading.
I mention above the alcohol should be the "denatured" kind that is used as a shellac thinner.
Rubbing alcohol is only about 70% alcohol, the rest being water and IMO it doesn't do a very good job of removing oil.