I never had luck swaddling with a blanket because I could never find one big enough. I had a swaddler from Target that worked fine when she was little but by 3 months she was breaking out of it all the time, so I know where you're coming from.
The miracle blanket is what worked best for us too. We live in a hot climate and just swaddled her over a diaper, no other clothes and she was fine. We do have AC, but it still gets pretty hot even at night. The miracle blanket has a pouch for baby's feet and a long strip of cloth that wraps around baby's body a couple times to hold it in place, there is no velcro. The material is cotton t-shirt-like material so it breathes and is cool.
HTH