[drh4683]

The sets coming from a clean non-smoker home is the key. If it's got grey fluffy dust inside, like most sets from clean homes, then they come back looking like new with minimal effort. I use a very small portable electric air compressor regulated down to about 20 PSI so any loose labels don't get torn or blown off. I do that in combination with a soft bristled paint brush throughout the chassis. After that, the tops of tubes are carefully wiped off with a water dampened cloth being careful not to wipe off any of the original markings on the tube. That's about it.