I recall when TVs had mechanical rotary switches for tuners back in the early 60's. My Dad used to spray down the contacts once a year. Then, early 70's I start my career in electronics.
The silicone spray for contact cleaner is still in use today. Great stuff, avoids corrosion, cleans, helps make much better contact. I keep a couple of cans around for all kinds of use, both electrical and mechanica. Available at Radio Shack (ouch), WalMart, or any automotive store. Ace has them as well.
The new style pushbutton switch has had a defect in the early production. They have been modded by the contractor and upgraded. Look for the more recent dates if you purchase one. You don't want an old one. I don't recall the date of the newly produced one right off hand. Short on time to research right now.