|Kettlebells have around|
My opinion is that kettlebell exercises if done smoothly could possibly be used for a warm up or conditioning. Even in that respect, there are much better alternatives. Kettlebell exercises serve little purpose as it relates to strength and muscle gain. While designing a workout program, use the highest form of technology available. Kettlebells are a "horse and buggy" era technology.
Here's an article that finally examines the kettlebell workout fad: