Any beer will do, so don't think it has to be something specific or expensive. Take a peek in the fridge; maybe you have a few leftovers that your friends left behind. The beer needs to be flat for this treatment. Do so by leaving it open for an hour or two (or grab the ones left out from the party that were not finished). Douse your dry hair with flat beer, covering your entire head. Make sure to do this over the sink or tub. Don't bring glass into the shower - we don't need an accident and trip to the ER just for trying out this new hair treatment. Leave the beer in your hair until it dries completely. You can use the time to clean up from your St. Paddy's party. Once it dries, hop in the shower and wash, condition and style your hair as usual.
You'll be able to tell how great your hair feels immediately afterward. This treatment is something that you can do as often as you want, but I don't see the need for more that once a week. What a great way to use beer that won't add extra calories or require a bigger pant size. Healthy, shiny hair is always in style!