Deoxit is a name brand of contact cleaner. What you have will probably work, but let's hope those old trimmers don't fall apart. They weren't very good quality even when new.
Unplug it, put it on the bench with a rag or paper towel in the appropriate place to catch the residue, lightly spray it, gently work it back and forth, repeat, turn all the way down, and then readjust. Good luck.