In the very short video below, rod maker Marc Aroner shows you how simple it is to clean the ferrules on your rod. Please take a moment to watch this & then apply this practice on your rods, if don't already make this part of your rod cleaning routine.
(NOTE: Marc uses a non-abrasive soap on his ferrules. You can also use bees wax, but the old wax must be removed from the male slide with a quick wipe from a soft rag & some rubbing alcohol. Bees wax is great for loose fitting ferrules, too. It hangs in & lasts a little longer than the soap, but it also holds more dirt, too so there are benefits & drawbacks to either soap or bees wax on your ferrules. The choice is yours which is best.)