Short answers, pulled from the story.
Workers used flat rocks known as beetling-stones or wooden implements called washing paddles to remove dirt from fabric. Sometimes they utilized a battling-block made of wood instead of stone.
The organization faced targeting between 1847 and 1957 during the Second Red Scare. This period saw a strong decline in its numbers after government intervention.
Drying at sixty degrees Celsius for thirty minutes kills many parasites including house dust mites. Just over ten minutes is sufficient to kill mites as well.
Florida explicitly guarantees a right to dry through legislation. No other state has such clearcut laws regarding outdoor clotheslines yet.