I received a soda stream as a gift before I started brewing and loved it. Only really used it for water. Then I made a my first fermented beverage, a wild fermented mead. After a month or so, I tried it still and thought, "Hey, let's carb this stuff up and try it!" It was much better but made a bit of a mess. Nothing crazy, just some foam overage.
After my first home brew came out of the secondary, I used the soda stream plastic bottle to carbonate a liter right away to test out the final product. It worked great! The trick is to let out the pressure slowly. It takes about a minute to release the pressure without a huge foam up. I have washed out the whole device after a foam up with no problems or beer favored water later on.
Take your time and it will be fine.