I re-read your post and there are several things that you could clarify in order to provide meaningful advice. First, you say you got distortion "at times." Was this distortion correlated with anything like crescendos, loud passages, inner grooves, outer grooves? Any commonality of playback conditions when this distortion occurred? Second, were you cleaning your stylus prior to the noticed distortion and accumulation of gunk? Third, was this gunk accumulation evenly distributed on the stylus or was it an accumulation that was centered around the upper part of the diamond where it meets the shank? Any accumulation of debris I've ever seen has always been where the stylus meets the shank, the actual stylus has been pretty clean. Even the nasty used cartridge with the stylus gunk I mentioned earlier played and sounded just fine, as all the debris was above the stylus/record interface.