I've used the Estes Universal AstroCam HD Rocket Camera and Holder a few times and did not have any problems with it.
I strapped it on to my Super Big Bertha and my Nike Smoke Pro Series as launch vehicles and didn't have any problem with it detaching or anything like that.
Got two really great videos out of three flights (didn't get it to activate on the first flight--my fault) and will be flying it again in this strap-on mode next time I can get to my launch site.
The slower liftoff profile of the Super Big Bertha produced the better of the two videos and I plan to use the Der Big Max as a launch vehicle next time I try for more videos. F-sized engines (BP, not composite).
So, I guess to answer the original concern here---Strapping on works ok. But if you're worried about it falling off, just get the AstroCam rocket from Estes as the camera is built-in. About a ten dollar difference.