I didn't mean to imply that I thought you were doing the wrong thing in using it. I was just amazed at how much prep work was needed before you even broke the seal on the can.
There's risk associated with just getting out of bed in the morning, so that isn't a good reason for using it but cost is. The last time I pulled a head to replace a head gasket was on a '49 Merc flat-head V8. That was like pulling the head on my lawn mower. I don't know what kind of work you'd have in pulling the head on your Subaru.
Jack