On the Nengun pages a generic performance mod for the ZZW30:
https://www.nengun.com/greddy/universal-kangaroo-washer-bag
They list it as Greddy. I found the exact same from an Egyptian seller for less than a third. As I commented, it works a treat and imo worthwhile for a non-daily.
(https://myalbum.com/photo/sp5bQSFdmP4i/1k0.jpg)