Not sure how long, different cloth mask might differ too. most of which i encountered so far were daily thankfully haha
But really wash once a week is quite disgusting to me even if that's the recommended.. those invisible stuff like germs accumulated or what is just unimaginable..
hopefully they did or maybe like me, still got some earlier mask unused (cause some of my family member prefer to use disposal ones, while i will use cloth for short trip like going down nearby supermarket or jogging).. anyway there's a recommended limit to the number of wash, anything beyond that, the mask is literally just a cloth and have no protection ability..