I wouldn't use the poly batting!!!
Use warm and natural and some INSUL BRIGHT, it is $6.99 at Joann's. It is the batting with the silver wafer in the middle. I have a remnant that only cost me $1.07 for 11" sitting right in front of me. You wouldn't want to be liable for burns!
If you want to use only poly, make sure that you attach a hang tag or stitch in a label that states that these are for decorative use only.............