Well I washed by handwashing (bit of laundry detergent and water, rinsed a few times, took only a few minutes) and let them air dry. Sometimes on the line, sometimes inside pegged to a coathanger. They were snug tight around the waist, came up above the nappy, and left seam marks on her tummy and back. They were snug with a bit of room around the nappy. And they were a bit loose around the legs, so I had to change her often, including rompersuit or pants, as the pilcher allowed leakage. I guess different brands have different shapes. If you are looking for PVC covers because of cost, try to find ones with wide cloth elastic around the legs. Some have that, to keep it snug to the nappy, others use the thinner elastic in the seam, and that's why they can leak.

If cost is an issue, try googling for businesses that do layaway or in Aus layby. I know of one Australian site that does do layby. Go for the PVC, its not terribly bad. Try to allow for lots of nappy free time, lying on tummy on a towel.