He's actually spraying the manually adjustable potentiometer (audio volume control pot) intending for the contact lubricant to get inside its moving parts and condition the electrical "wiper" inside the pot for the precise reason that it is an unsoldered circuit connection and subject to unreliable contact from either or both of disuse or overuse.
When an analog volume control responds unevenly or makes static when adjusted, try technician-in-a-can, no soldering usually involved.
