I'm not too tickled about either of those. Rislone was mostly Kerosene back in the day but it was all that guys knew about. I prefer BG or Macs. It has no harmful effect to the engine, does a good job, and follow directions. I guess if you sludge really is sludge, you might have to reapply the set up on the next change or tear some sheet metal off and clean it right allowing the oil to do it's job and any flushes you use to do theirs better.