Hi Shadagirl -
I washed a costume and posted about it on old bhuz - here's the link:
http://ads.bhuz.com/forum/topic.asp?...6&SearchTerms=,
I used a mix of washing powder and detergent, both are much gentler than woolite. And here's another article about washing costumes, from Princess Farhana on BDLA.
http://www.bellydancela.com/CostumeCareRepair.html