I own one at home.  It is an excellent product.  No filters.  The extracted dirt, dust, and air are drawn through -- the dirt/dust is deposited in a water tank -- and the air is passed through the water tank as tiny air bubbles.  After vacuuming an area the water and its contents are poured down a toilet.....it is amazing how much dust is collected!  The down side is that they are not cheap.  The up side is that there is no dust in the air and the floors and carpets are clean!  My wife and son and dust allergies and the "Rainbow" product seems to help.  I would imagine that this product could have a use in a historic house environment as well.
Wesley Creel
Administrator of Programs
Pink Palace Family of Museums
Memphis, TN
  ----- Original Message ----- 
  From: John Martinson 
  To: [log in to unmask] 
  Sent: Thursday, April 19, 2001 2:15 PM
  Subject: Re: Living history museums--vacuums...



  Has anybody worked with the "rainbow" vacuum, using the water filter?  It is 
  EXPENSIVE!  But seems with the demonstration today to work pretty good. 

  Best, 

  John Martinson 
  Curator of Collections 
  This Is The Place Heritage Park 
  Salt Lake City, UT 
  http://ourworld.cs.com/john29mart/