im no expert on this, however i had a customer once who had her daughters dog for a week, after giving the dog back the fleas stayed, she tried everything to get rid of them, finaly she called me in to clean her carpets, i cleaned them in the normal way HWE.
one year later she had me back, thats when she told me that after i cleaned her carpets the first time she never saw fleas again!, i was unsure, but she was adiment it was that got rid of them, HWE.