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For heavily soiled areas or to ensure no cleaning solution residue is left behind, rinse the carpet. Empty and refill the clean water tank with only plain hot tap water. Repeat the extraction process (Step 3) over the cleaned area, this time without adding cleaning solution and optionally without scrubbing, relying solely on hot water spray and suction. Repeat until the extracted water appears clear. If initial stains are still visible, repeat the entire cleaning process from pre-treatment.