It's impossible to eat habaneros like an onion. For one thing, you can't, they're too small. There's no such thing as a big bite out of a habanaro. For another thing, if you had a habanero that big your throught would probably swell up.

If you're bold and young enough and mildly insane you can take a habanero in two bites. Or if you're totally insane, chomp one habanaro in one bite. Oh my god. Have plenty of milk or beer (you might need hard likker, after two bites on a habanero you'll either be halfway passed out or dead anyway) on hand. And be prepared with ointment a few hours later.

The alcohol and/or milk is to dissolve the active ingredient in the pepper, of course. The active ingredient is soluable in fatty liquids (like milk) or alcohol but not in water. You can drink gallons of water without getting rid of habanero.

I have only used a major habanero chomp to impress friends who really knew what I was doing. Only nibbled for people who didn't really understand. Never did an entire pepper.