HOBIBEARUnisex Wide Barefoot Minimalist Shoes for Men Women Outdoor Trail Walking Shoes

Are the size options Women's sizes, or Men's sizes?

Can I pop these in the washing machine?

Im size 6 uk. Whats best for me the 5.5 or the 6.5?

Sizing. I have a 27cm foot length and 10cm width foot. Could anybody tell me which would be my best size to order?