Lol no flash bangs and no rolling anything..
There are very basic building clearing skills you learn. Then you move onto more advanced.
We train with SWAT on how to move through buildings.
While that little rolling ball does seem like it would work, I would never use one.
The bad guy would know you were fixing to walk into the room, so you failed.
Think, if it impaired his vision, unless I'm wearing sunglasses how would I not be affected. Flash bangs don't disorient people outside of the room and there's no way to avoid the affects. Even if you close you're eyes the concussion is going to set you down QUICK.
In SWAT callouts unless there is some reason to go in quickly (given patrol cops or first responders would probably take the roll of SWAT if it was that important) flashbangs are a last resort used with actually physically going in under certain circumstances.
In todays world, patrol cops who are first responders often take the roll of SWAT when they need to go in somewhere and don't have time to wait on SWAT. Flash bangs aren't given to them, only many many many nights and days of practicing how to do it with yourself and you're gun.