How do I remove gunk from a Lyra Delos cartridge?

I was getting distortion at times when playing lps.Last week I took the turntable to a high end store in Manhattan and they said they would see if they could locate the problem.Everything checked out fine,but they did find what they called gunk on the stylus that you can only see with a magnifying glass and that they were unable to remove the gunk.The store is not a Lyra dealer so maybe they were being cautious when trying to remove the gunk because they did not want to take the chance of damaging the stylus.I will be going to the store tomorrow and I will ask them what methods they used to try and remove the gunk.If someone can give me some advice on removing the gunk I would appreciate it or if you think I would be better off getting in touch with the manufacturer.I'm worried about damage to the stylus. My turntable is a VPI 19 MKiii with a Audioquest PT-6 tonearm.I am thinking about upgrading to a VPI 9 Signature or getting a new turntable if it is more cost efficent. Thanks