For heavily stained carpets the following process should be followed if you are using a pre-treater:
1. Use the SteamBuster to lift the stain
2. Use the pre-treating solution making sure that you follow the manufacturers directions for that product
3. Use the SteamBuster to finish the job after applying the pre-treater.
IMPORTANT! Please remember that the only solution to be placed in the SteamBuster is water.