I doubt a hose clamp would be anything like stiff enough to compress that shield edge. I just used a hammer as the video showed, and it closed up enough to hold in place.
The sprag I used had a different type of circlip which protruded through slots in the casing sufficient to stop the unit seating in the drum. I could have reduced the 'ears', but once that circlip was out, I found it impossible to get the **** thing to go back anyway, so just used the simple circlip that was in there before. I'm not sure the circlip does much more than take up space, as there is no recess for it to go into.