I kinda doubt the effectiveness of this gadget in normal shooting circumstances.
Unless shooting in a really tight room with super low ceilings, that gadget may not be very effective. Just my ho.
U may do better getting a pop up diffuser: DIY, get a slightly thick white cloth and wrap it around. Get it to stay there by sewing some elastic rubber around the edges- get the wifey to do it for u- its free, with love, and it works. And the range is longer too.