The exterior of the speaker sits flush with your drywall, giving it a sleek and smooth appearance. Once your in-wall speakers are in place, you can connect it to the power and amplification sources to get that rich, deep sound you want in your outdoor space.
Drying oils will change from liquid to a solid film when exposed to oxygen in the air. Nut oils (boiled linseed, tung, etc.) are drying oils, but vegetable (peanut, olive) and mineral oils are non-drying. Edible mineral oil is popular on food contact items, like cutting boards. However, non-drying oils stay wet indefinitely, and they will wash off when the board is scrubbed with soap and water. Because they do not dry to a solid film, non-drying oils are considered a wood treatment, but not a finish.
Wood cutting boards should be regularly seasoned with a good quality cutting board oil. You can find them in most hardware stores. Mineral oil is typically used, since it does not go rancid. Do not use vegetable oil or olive oil.