The pit does not have any magical properties. What turns the guac brown is the air. If you can keep air from touching the guac then it will stay green. The pit will keep a portion away from the air, but what is more affective is to put plastic wrap over it and push it right down onto the surface.
Denuded skin is just another way of saying that the top layer (epidermis) of skin is gone...either from friction (abrasion or tear), trauma (tape burns), or severe rashes, or from a stage II pressure ulcer.
Bed Sores. Bedsores are also known as pressure sores or pressure ulcers. They are a type of injury which is inflicted on both the skin and the layers of tissue which reside underneath it. Bedsores come as a result of prolonged pressure on a specific area of skin. Since they are caused by pressure, bedsores are often present on the bony areas of the body which do not absorb pressure as well. The buttocks, hips, heels and ankles are all common locations for bedsores to be present.