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The service adjustments with the threaded shafts are tuned inductors or tuned transformers...the tuning is magnetic permeability tuning. The screw threads move a small slug of ferrite or copper in and out of the core of the coil. Unless they are physically stuck (and you need to adjust one for some reason) and can't move they don't require or benefit from cleaning. Also if the tuned coil is not in the horizontal circuit DON'T turn it at all....Most tuned coils/transformers are in the tuner and IF circuits. The tuner and IF stages require precise electrical alignment for the set to function...This alignment 97% of the time is still fine as it sits today. If you disturb any tuner or video IF adjustments you will have to buy a lot of very expensive equipment and spend a large amount of time learning the borderline dark art of television alignment.
TV chassis can only have voltage on them if plugged in to the wall, and that usually only goes for hot chassis sets. The capacitors can store voltage, the lytics and CRT are the only ones that can hold it long enough to get you. The lytics typically self discharge within a minute (you can take a clip lead connect one end to chassis and touch the other end to the positive terminals to ensure discharge if you're worried), but the CRT can hold it's charge for days....The good thing about the CRT is it can only store an amount of charge that is close to the worst static charge you can get shuffling feet on carpet and touching a doorknob, but it's still bad enough to trigger reflexes (and what you elbow on reflex can be sharp...ask me how I know) so if you need to poke around in the HV cage or remove the CRT discharging the CRT is strongly recommended. To do so connect an end of a clip lead to chassis, connect the other end to one end of a 1M ohm resistor, connect the other end of the resistor to the metal blade of a well insulated screwdriver, then holding the driver by the insulated plastic handle slide the blade under the HV suction cup connector (some 50s sets don't have a suction cup and just leave the metal connector exposed) on the side of the CRT and hold it to the metal for 30 seconds.
You can do without the resistor and connect the clip lead directly to the screwdriver but that allows a phenomenon in CRTs known as dielectric recovery where a fair portion of the charge magically reappears after a few seconds or minutes.... I've been bit by it and uttered more swear words because of it than I can remember.
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