Can't believe that worked for you. I thought that drill attachment was universally awful. @corar78 had the exact same loose fit problem I did, just a total racket when you try to use it. I tried it once on a small tile job and the wobble was so bad I thought the drill was going to shake apart. You must have gotten the one unit from a good batch.
Same thing happened with a universal grout blade for my drill. The fit was always loose, made a horrible grinding sound. Ended up just mixing by hand, total waste of money.