You want to do this safely. Please be careful.
Since you are cleaning the contacts of your tube sockets, you should do a complete job and clean all the contacts. This would include the tube sockets, the tube pins, every jack on the amp, and all the pots. To do this properly, the chassis should be removed from the case.
Be very careful when working within the amp. When you turn it off, there are potentially lethal voltages stored in the capacitors. They can still remain charged long after the amp is turned off. To be safe, it is best to discharge the capacitors before working on the amp.
One way to to this is to play your instrument through the amp and pull the power plug while playing hard. This will put a demand on the power supply and drain the caps after the power is off. You will hear a distorted sound as the caps discharge. On some amps leaving the amp in playing mode (not standby) with the power switch on will continue to discharge the caps over the next several hours. Your amp may or may not be designed to do this. So on to step two. Remove the chassis from the cabinet. Use a discharge tool to discharge the capacitors. This is a wire with an alligator clip at one end and a resistor, the value isn't important around 200K 2W is fine, with a probe or alligator clip at the other end. Often the resistor is attached to a stick for safety reasons. Here is an example of
one that weber sells but you can easily make one with parts from Radio Shack.
The idea is, you attach the alligator clip to ground and then carefully hold the other end on the + side of each capacitor in the power supply for a minute or so. These are the usually the bigger capacitors in the amp. This gives the capacitor a path to discharge quickly. Be careful doing this as there is enough energy in a fully charged capacitor to melt the end of a screwdriver. Once you have done all the caps, connect a voltmeter set on DC volts and test each cap. Each cap should read zero volts when they are fully discharged.
DeOxit will remove oxidation and leave a protective lubricant. Follow the instructions carefully, including shaking the container well before and during use.
Put a little DeOxit one a Q-tip and clean each jack where ever it makes contact with a plug. Put a drop in each pot and move the knob back and forth throughout the entire range of travel to work the liquid in everywhere. Clean the tube socket contacts. I find that a pipe cleaner can be useful here. Clean the tube pins as well. Use it everywhere there is an electrical connection and metal on metal contact.
