Ours are varnished. Vacuum them first to remove most of the loose stuff. Then a sponge in a solution of dishwashing detergent (like Joy or Dawn or Palmolive) with warm water
, and sponge them off.
If they were unsealed, mold
may have become established in them, making them look "dirty", blackish. In that case, 10 drops of clove oil
to 2 cups warm water
, and sponge them thoroughly with that. It is said that the clove oil penetrates the pores the molds secure in, and kill it there. If the boat is in a highly humid area, you do not use de-humidifiers, and the cane is unsealed, you may have to do this every three months or so. Time will tell.
At any rate, good luck with it. I like the cane we have; the air circulation is great.