FWIW Watco is a mix of oil and varnish. It is pretty, doesn't build a film, and will blotch with exposure to moisture. It's not the worst choice in the world, but there certainly are better. It may be just fine to refresh a factory finish if it is going over the finish, rather that on naked wood. It can't be worse than regular oil. It is an interior wood finish, and furniture that has been finished with it will get rings if you leave a wet glass on it.
If you are looking for a finish from a hardware store, maybe poly that has been rubbed out to a matte finish? Get a wiping poly or thin standard gloss poly to 50% poly 50% mineral spirits and wipe on. It can be done without looking too glossy.
Section 2 - Composition / Information On Ingredients
Chemical Name CAS Number Weight % Less ThanACGIH TLV-TWA ACGIH TLV-STELOSHA PEL-TWA OSHA PEL-CEILING
Mineral Spirits 8052-41-3 60.0 NE NE 100 ppm NE
aromatic petroleum distillates 64742-95-6 5.0 NE NE N.E. N.E.
Dipropylene Glycol Monomethyl Ether34590-94-8 5.0 100 ppm N.E. N.E. N.E.
Stoddard Solvent 8052-41-3 5.0 100 PPM 100 PPM
While hard to read as it copied and pasted, the list above is the actual ingredient list of Watco Danish Oil, the assumed finish being discussed as Watco because it is their best-known, biggest selling mixture.
It has no resins, which is a requirement for varnish.
Gloss Poly rubbed out is an excellent choice with wax for flattening further... never use matte finishes as the flatting agents are usually just silica which makes the finishes far less durable and less waterproof.
Adding oil to the poly will make it easier to apply to get the desired look.
