Use warm/hot water for washing soiled clothing, this releases more saponin (soap) from the SoapNuts. Also reduce the clothes in the machine to allow clothes to move freely. SoapNuts won't remove stubborn stains but will remove general grime. You may presoak clothes in liquid SoapNuts prior to washing for extra cleaning power if required. Or your could presoak the clothes overnight in Oxygen bleach and then wash as normal with SoapNuts.