Just use your bathtub. Put the soap and water in first, then the quilt. Do some hand agitation, then drain the tub. Put in fresh water, hand agitate, then drain and repeat until the water runs clear. Use a clothes basket to take the quilt out of the tub so you don't break any threads - it will be heavy!! Lay some sheets on the lawn, spread out the quilt, cover with a sheet to protect from direct light and birds.