That is a good idea, I'm too curious if for some unknown reason this isn't recommended....
I'm hoping that stirred hot wort isn't bad. I used my sanitized paint stir thing and drill. Went from 218 to 90 in 4 minutes with a homemade 3/8" 25' immersion chiller. Another 30 seconds I was at 80. Arm got tired, needed a beer. So I typed this post.
80 to 70 a little slower. Guessing that's cuz I'm getting closer to ground water temp (50).