We have a more complex then average phone system in our house and as it aged it gradually generated more static. Also as we added CFLs other symptoms developed which will be discussed in a different post. Here's a link that shows the extent of the installation that needed "cleaning up".
http://www.sfpasc.com/x10/OldtimersTelphoneSystemDiagram.pdfLooking into the probem two things became obvious. First, a lot of the connectors and switches were aging and generating contact noise. Second, because these same connections were no longer as clean as they were when they were installed some of the circuits were becoming unbalanced, which is a major source of induced line noise pick up.
Research led me to a 20 year old product that I had forgotten about, Stabilant 22. It is NOT a contact cleaner. "It is an initially non-conductive polymer that switches to a conductive state when used in a thin film within the interstices of a contact, while remaining non-conductive on the insulating surfaces between adjacent contacts." It is pricey but it really works. I applied it to virtually all the connections and switches in our phone system and it restored things to better than new condition. Without Stabilant 22 I would have been forced to individually test and replace all the connectors and some of the phone equipment itself. The whole job took about three hours.
Here's a link to one of the US distributors of the product. There are others but I was familiar with this one. There is a link at the bottom of this URL to the manufacturer's own web site.
http://www.posthorn.com/Stab_2.htmlI purchased the 5 ml field kit which comes with a dilutant bottle and 3 applicators. I also had to buy a small bottle of 91% isopropanol (alcohol) to dilute it. They recommend 99% but this is much less expensive and works quite well, in fact once you open a bottle of 99% it starts absorbing moisture from the air right away and quickly becomes much less pure, so why spend the extra money.
The kit will make 30 ml of the diluted product. I've used less then 5 ml of that so far, so a little bit goes a long way.
I'm also gradually applying it to all the A/V connections in the house with noticable improvement on many of those circuits. It can also be used to clean up press fit connections inside computers although I haven't tried that as yet
Overall I found this to be a very cost effective solution to our problems.