Lancaster, England, United Kingdom
The main thing I think you'd have to watch out for is the colour temperature and light spectrum it throws out.
Most of the plastic ones can turn your light very blue (and some of the cloth ones make it warmer), and both can block certain colours.
I'd be tempted to use the frame, but replace the material with some white ripstop. You'd probably want to aim your flash towards the back and let it bounce forward for a more even spread. Then it's essentially acting the way a Lastolite HiLite does (which I use as a giant softbox often).
It looks as though there would be a lot of light lost and scattered due to all sides being translucent. And there is no internal baffle for diffusion. It may have a somewhat diffused bare bulb effect though used as is.