I found that using my wood burning tool I can burn the frayed fabric threads. Just do not hold it in one place too long. Works good on cut work projects also. I am working on a rag style wall hanging using embroidered designs. If I can figure out how to post a picture of it when I am finished I will show everyone.
They are handsome fellows. There are a lot of things to remember when making them and I usually forget at least one of them!
I dont see anything wrong with your owls, love the fabric you used, great work