I use polythene dust sheets from Wickes (£10.00 for 10) or Screwfix (£1.99 for 2) and put them down first with a fabric dust sheet over the top. I use twill dust sheets, old bed sheets...you name it. It takes about 20 - 30 mins to set up depending on the room but you save time later as you don't have to worry about mess etc.
I let the fabric sheets get pretty messy before I wash 'em as they don't come into contact with the carpet or flooring. I just shake 'em off before the next job. The only reason I put something on the plastic sheets is to catch the pva as it will stay wet for days on the plastic sheets and ends up getting on the carpets when you take them up. I only usually use one coat of pva and tend to lash it on with a roller. I also find that if you drop any gear (which of course I never do

) it tends to splash less on the fabric sheets. They also stop my hop-up from tearing the plastic
I always factor the polythene sheets into the price of a room (£10.00) but usually get away with using 4 or 5 so end up making off it.
I get the same problem with the missus and the washer though mate. If they're really bad I'll take 'em to the laundrette and fcuk their machines up instead ;D