Danish Oil and TruOil are very similar products that use polymerising oils. TruOil is linseed oil based, whilst Danish Oil can be tung oil or linseed oil based depending on the manufacturer.
I'd apply some to the back of the neck to stop it getting dirty quickly. Once dirt gets into the wood, it's hard to get out without sanding it down.
You'd treat Pau Ferro like Rosewood, so just apply an occasional wipe of lemon oil or boiled linseed oil.