It is perfectly possible to get to 10% and below without ANY supplements, as an older female coach I may not have those levels personally but my athletes do, no roids, no creatine, no protein powders, no pre workouts, just normal food. training 1 hour 4 days per week in the gym in prep for competition every 3 months or so plus a little bit of team sports for fun.
A 1000 cal deficit is not a good idea, you will loose muscle with a high deficit when you are at a low bf%