Joni, Thanks for the compliment. The wings don't affect stalling if the body of the bag and wings are soft enough. I actually find them to help stabilize and control the bag as it settles on the foot or other body part. Don't use rice. It changes, absorbs moisture and disintegrates quickly.
Plastic pellets are the raw material of nearly all plastic fabrication.
Look for a plastic bag factory or injection molding or plastics extrusion plant. Good luck sewing and don' t forget to share your products with the list. Joni, Not an auto email. David's work is exceptional. He is a true master.