Thanks to the advice given by several members on this forum recently, I bought some from Maplins despite my scepticism. I cleaned all my phono plugs, sockets and speaker banana plugs using cotton buds.... even mains plugs
. It all took about 30 minutes and WOW!! Noticed the difference straightaway - clearer trebles, lovely vocals, imaging, tighter bass! Best £7 I have spent in a long time. But then my system is about 10 years old and this was the first clean! I would recommend that everyone gives their sockets a good clean once a year!