ARIATWomen's Warm Soft Acrylic/Wool Blend Upper Indoor/Outdoor Rubber Bottom Bootie Slippers

Has anyone tried washing these slippers? If so, any tips? I bought mine in the white so I need to get prepared! :)

I wear a size 10 would X Large be the right size and do they have a good arch support ?

What size for a 6.5?

Which size, small or med, for women size 7??