I used boiled linseed oil, about 5 coats thinned 50/50 with mineral spirits, then tru-oil, both sprayed on with an air brush, both cut 50/50 with mineral spirits about 20 coats.
Cutting it 50/50 thins the material and makes for easy spraying and thinner, quicker drying coats.
I'd wait 2 days between coats.
My job was a refinish, not a refresh and I sanded between coats.
I've tried thinning and rubbing it in as well as brushing, but an air brush gives a much better finish.
Boiled linseed oil is used as a paint binder or as a wood finish on its own. Heating the oil makes it polymerize or oxidise more readily, effectively shortening the drying time. Today most products labeled as "boiled linseed oil" are a combination of raw linseed oil, petroleum-based solvent and metallic dryers.
If your old finish is linseed oil, the tru-oil will go on fine over it. Just wipe it down with mineral spirits to remove oil, grease, or other impuritiies.