If our clothing was very soiled we had to help Mom by rubbing the collars, hems, etc. with Sunlight soap and then scrubbing them on the board. White socks, underwear too if necessary. We used cold water first to "loosen the dirt", then soapy warm or hot water, then a cold rinse. Sheets were soaked overnight in the bathtub in cold water, and later Mom used bluing in the water to keep the whites from yellowing. The sun would do the rest as they blew on the line.