It is generally not recommended that you use any type of cleaner other than a pure solvent like xylene or alcohol on tube pins. The reason is that because of the heat on the pins of the tube from the filament and plate, the "cleaner" can turn into varnish over time and cause more problems down the road - problems which cannot be solved by any other means than replacing the tube socket.

But considering you never listen to any advise from anybody here, just go ahead and slother that contact cleaner all over 'yer tube pins.