Some claim that wet-cleaning methods could cause issues with allergens since dust mites and molds thrive in humid and warm conditions. That might be true if the steam cleaning is not done properly, such as with DIY rental steam cleaners which lack the heat and suction power to be effective. They are also often not cleaned properly which means, instead of removing allergens, they can be responsible for bringing dust mites and other allergens into your home. Professional truck-mounted steam cleaning, on the other hand, has been proven to reduce allergens in carpet and kill dust mites. Accordion Content