Ive heard of plenty such as myself takign slin on a cut.. im not doing a show, I think its possible to run preconest especially if your going 20 weeks out or so and dosing carbs perfect avoiding all fats.
I have used insulin (humulin R) for precontest (using a protein/carb/low fat diet) seem to help keep my muscle better, but I started out pretty lean, and needed to lose only about 15 pounds to be in contest shape....
just make sure you counting carbs, you don't want to crash and end up eating the house. Oh, and don't take it if your depleting.
This dumb ass took 10u on his first carb meal after depleting for
3 days. He spent 3 days in the hospital and missed his show.