Denatured isopropyl alcohol. Rubbing alcohol has water in it and can cause the laminations of the head to rust. Yes you can use alcohol on the capstan and pinch roller. Be careful not to get things to wet. The Q-Tip only needs to be moist not dripping wet. You do not want to get the alcohol in the capstan shaft bearings, or the pinch roller bushing.
The DM10, "Turn the deck off. Turn the demaganetizer on and slowly", underlined, "bring the tip as close as possible to the record/play head {it is not necessary to demagnetize the erase head}. Do not make contact with the head unless the tip of the demagnetizer is covered with thin vinyl or rubber to avoid scratching the surface of the head. Move the demagnetizer tip slowly",underlined, "in a random pattern about the surface of the head for at least 10 seconds and then slowly", underlined, "move it toward the capstan. Repeat with the capstan, and then slowly", underlined, "withdraw the demagnetizer. Turn it off after it is at least 2 feet from the deck. Never turn the demagnetizer off while it is close to the head or capstan as this may semi-permanently magnetize the metal part"
