Always read and use the care instructions on your yarn's label. If you need help interpreting the symbols used on the label, check our Yarn Label Symbols page.
Generally, you can machine wash nylons, but it does not affect it's softness. It is not advisable to machine dry or block a nylon garment with heat, as it can permanently lose it's body and sag.
Skein Lane recommends using a "wool wash" product such as Eucalan, and tepid water (not cold); it's not just for wools. Never use Woolite, as it contains a bleaching agent that can discolor your yarn. You may also add touch of hair conditioner to rinse water for extra softness.
Do not wring or twist the wet item. Wrap in a towel and gently squeeze out the excess water before laying flat to dry.