If you are going to use a wooden ramrod, you really ought to properly season it to prevent it from breaking in your hand.

Get a galvanized iron pipe about an inch inside diameter (threaded on each end) long enough to put your ramrod in it and a cap for each end. Fill the pipe with kerosene, cap it, and let the ramrod soak for a few months.

When you take it out, let it dry and you will find it to be quite flexible, and almost unbreakable. This is much better than having a dry wooden ramrod break and stick through your hand. I picked up this technique from an old Dixie Gun Works Catalog's Reference Section.

I can see how that would work.
I would think any light oil would absorb completely into the wood.
Kerosene would evaporate from the wood sooner than oil.
It is pretty flammable as well. We used to soak hammer /axe handles in oil for weeks before use. The wood would swell and keep the head tight for a long time.

Just an old carpenter' opinion.

RE: Replacement ramrod
IMO, the the best, strongest ramrods made were those TC used to make before their plant fire...resin impregnated ramrods...wooden, good looking, darn near as strongas steel, etc