Mixer for mashing and cooling?

So I'm about to do my first 10 gallon batch and am preparing to cool the wort as fast as I can since I've only got a 25" immersion chiller and a 25" pre-chiller. I've done some reading on the forum and it seems people have success with paint mixers attached to hand held drills. I looked on Home Depot and found this. Will this get a pretty good whirlpool going? It's hard to tell since it doesn't have fins like an airplane prop. This looks like it would double as a good mash paddle too.

I've been considering a similar mixer. My only concern would be the paint and the type of metal it's made from. It's most likely not food-safe.