Hand-sewing Without Seam Allowance?

I read in one of LJ's older posts that a blanket stitch doesn't need a seam allowance.
Is this legit (at least for novice sewers)? Does it really work?

I will be gluing most of the seams on the head (except for the ears and neck), but it would be amazing if I could sew without a seam allowance. For some reason I cannot stand them.