Yes - just like that! Looks like a very easy thing to do - and it really is. But not for the first few times 
Contrast shower is known to have great benefits not only to the skin: people using a contrast shower every day get sick less, they feel better and younger. The same effect on our skin: contrast showers make the skin former, softer and looking better - right after the first shower!
How contrast shower works:
The principal is really similar to regular massage. Massaging the skin with your hands or a massage handle, the fat tissue is physically affected and touched. However, while using a contrast shower, deeper layers under the skin are affected and stimulated. This works like a deep-tissue massage for cellulite affected skin.
Contrast shower works best when done regularly: every day after taking a shower, as a shower finishing procedure. You will mention your skin getting red - and this really shows that cold water flows really work.
After the shower, it is necessary to apply cream or lotion on the skin - especially the problem areas. Cellulite creams or lotions work best, but you can use just any hydrating lotion - to keep the skin soft and hydrated enough.
Contrast shower is a pleasant procedure to do when you get used to it. Especially when you start seeing the results - it is possible to mention a better looking skin in a couple of days, though just after the first procedure it really feels so soft and refreshed.
Swimming in a sea or lake has a similar effect - this is why you should not avoid to be in the water a lot during the summer season.