That made me laugh.

At least Darevie is honest about the fabric.
This kind of fully reflecting fabric is really easy to be damaged.
I've made this experience with 2 different pairs of shoes from different companies which had a fully reflective surface. Just by riding the fabric itself became ugly unamazingly fast.
I guess a shower with pure water would be absolutely okay.
Of course it's a valid question if I would like to have such a material as jacket... well.. for me I would answer that with a no.