Thats a tough one.....im not really sure myself but id probably put it in with my back stuff.....but really its a total body exercise so whateva works 4 u!
I had the same problem so I did them on shoulders and it didn't work to well for me. I do cleans when I do back because it fits into my schedule and because I do traps same day as back, and I also do them on shoulder day. I find it real effective on the same day as traps.