I had recently purchased a UK Plumb Atlantic copy of CSNY Deja Vu. It is an excellant copy, very quiet except at one spot on the title track and on Our House there is some dried dirt stuck in the groove I can't get out. They are both about a 1/8" long. I have a Nitty Gritty 1.5F1 and also tried hand cleaning. Anyone have any sugestions?