Step 1: Fly to a nice, toxic planet such as Quesh, Taris, or Hutta. The vault on Balmorra works as well.
|Image provided by the Holonet|
Step 3: Submerge.
Step 4: Run your varactyl around, it not only will dry your varactyl but it's good exercise.
WARNING: Do not use the above bathing method on your Grassland, Woodland, or Coastal Varactyl unless you wish to have an Irradiated Varactyl instead.