Your toes aren't really pointed inward just parallel and about shoulder width apart but it does feel that they're pointed inward just because their so used to being pointed outward. Squating with this form is much more difficult and only about 75% of your normal squatting weight can be used.
Make sure to go below parallel. I've found the other best exercises to build quap sweep are 1-leg hack squats, walking barbell lunges and 1-leg leg presses. But more than anything it just takes time.