Torticollis product?

My 3 month has Torticollis and I'm looking for a product to use in the crib to keep her head either straight or on the preferred side. Her pediatrician and physical therapist recommended tightly wrapping a burp cloth and putting it on the left side of her head (so she'd turn her head to the right where the issue is,) but she's so strong she just uses it as a head prop! Lol. The car seat and swing are not an issue, I can keep her head straight with wrapped burp clothes...it's just at night. She's sleeping through the night so it's long stretches on the "wrong side." I wake up still and turn her head, but it's not long before she turns it the opposite way.  Can anyone recommend some products?