New 100% linen Ralph Lauren pants - instructions say dry clean only. I did look through some old SF threads and there was mixed advice about whether it was safe to hand wash, machine wash, or dry clean in terms of shinkage. Right now the waist fits perfect, but the length is about 1-2 inches too long. So I wouldn't mind some shrinkage in the length, but I'm worried about the waist. Should I do some form of washing to try to pre-shrink before alteration, or do nothing?