Before 2000 Flushes could complete its national expansion westward, Vanish began disparaging advertising suggesting calcium hypochlorite toilet cleaners damaged plumbing.
In fall 1981, a group of manufacturers led by Twinoak (which made "120 Day Automatic Toilet Bowl Cleaner" since 1965) obtained an out-of-court settlement against Drackett Company, maker of Vanish.
[8] Al Eisen (as inventor of 2000 Flushes) made personal appearances in many early ads for the product, in which he holds up four fingers and boasts "It works up to four months!
[11] By 1998, flappers had been redesigned to withstand continuous immersion in 2000 Flushes or Clorox bowl cleaners, then the most popular products.
[12] A rival in-tank cleaner introduced by Vanish in 2000 caused problems until 2005, when new durability and marking requirements for flappers were added to the ASME A112.19.5 standard on "Flush Valves and Spuds for Water Closets, Urinals, and Tanks".