Now that the warmer weather is here, these are some of the products I use to spring clean some of those insulators found this past fall and winter. Obviously a soaking in oxalic acid ( I have the wood bleach strength) but usually get good results with half a can BKF mixed in a 2/3rds filled bucket. Also, ammonia for pin holes. Various glass cleansers(GLASS SCRUB) used with 0000(finest grade to prevent scratches) steel wool, dental pick, and an alligator clip to hold a piece of wool to scrub inside for more stubborn stuff.