Both Cramoline and Kontac have been used by many audiophiles over the years, and both have their advocates. There is also another "system" that I got from Audio Ideas Guide magazine that works well -- it involves using a cleaner called "TPC" ("The Perfect Connection" -- it looks a bit like a Handi-Wipe towelette) in combination with a plastic RCA jack that you insert into the component's RCA jack and then rotate the plastic jack, thereby scrubbing the surface of the component's jack.
Audio Ideas Guide magazine sells the cleaner and a pair of plastic RCA jacks for a modest price -- and you may also be able to acquire it from AudioAdvisor or a similar online audio retailer.
Audio Ideas Guide magazine sells the cleaner and a pair of plastic RCA jacks for a modest price -- and you may also be able to acquire it from AudioAdvisor or a similar online audio retailer.