Breaking my Doc Martens in, second try

I've had my boots for more than two years at this point, but I barely wear them because they hurt like hell to break in. My main grudge with them is the heel area; there's this crease at the back seam that digs into my foot.

Today, I wore them around the house with three layers of socks and gunned the back of them with a hair dryer, and I think it's been working, since I haven't gotten a blister. I'm gonna rinse and repeat this process until they feel like slippers.