As far as quenching is concerned, the importnat part is viscosity, or thickness of the oil.
You generally do not want to quench in water ( even water-hardening steels such as W1) unless you are an expert, because the
water is "too thin", boils off quickly, and quenches the steel too fast, resulting in glass-hard brittelness.
Yoou should tailor the oil to the steel involved, fast quenching (ie thin ) oils vs slow quenching ( ie thick ) oils.
Some foks like oils like olive oil because it smells nice, some like other oils for higher flash point.
I always "used to" use old crankcase oil, ie used 10w30. But bear in mind I was quenching random scrap for stuff like fire tongs, pokers, etc, and made specific stuff out of scavenged detroit leaf and coil springs. For those, crankcase oil was fine.
I have used olive oil, I never tried corn oil or canola, tho...
I have also been known to "bring out" the pattern of damascus ( aka pattern welding) with soda pop ( ie coke) .
So, having babbled on about all that, for your hammer, I would suggest getting just a couple of dabs of "casenite" on the hammer face, heat to cherry red, and quench OUTSIDE in a pint or so of whatever oil you have on hand....