In a 46-foot catamaran, a sea anchor will put an awful lot of stress on whatever it's attached to. I've been told, and I tend to agree, that I would only use a sea anchor if the engines are out and the storm is blowing me toward shore. Otherwise, I'd use a drogue (or motor away from shore).
You can rig drogue with a Y harness so you can adjust the angle. I've tried it (on a Catana 52) and it's pretty stable even without the autopilot, with a bungee cord holding the wheel.
If you don't have a series drogue, you should make sure and put some chain ahead of the drogue for weight, and use a long rope, so the drogue doesn't fly out of the water between waves.
Think ahead on how you will retrieve the drogue (or sea anchor, for that matter). It will take some winching.
I haven't used either a sea anchor or a drogue in a storm. I've had a sea anchor on a Bahia 46, but don't have one now on a Catana 52. Had drogues on both boats. I have tried out drogues, but not a sea anchor, in wind.