I've washed yards of plain tulle, but not put together in a tutu. In my front loader, it adjusts washing time and the tulle was done in just a few minutes. Just don't put it in the dryer. (it's pretty much dry when it comes out anyways!)
Ella has a store bought one that is attached to leggings that I have washed and dried several times now. It is fine, but if Isa's tutu is one that has been tied to elastic rather then sewn I would hand wash it, just so you don't have to go and possibly fix any strips
Re: Can tulle go in the washing machine?
https://www.essortment.com/home/tullefabriccar_snzf.htm
Looks like it's doable, but hand washing may be safer. Just avoid any heat apparently!
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