Yes, that method was controversial, for good reason. While a shock to the system such as cold water can help sort of "reset" the autonomous nervous system when in fight, flight, or flee mode (this is why splashing cold water on your face during an anxiety attack can help you calm down), having that done to you without consent can be extremely terrifying, and damaging, especially when you're already in panic mode. Forced sedation isn't any better, though.
A weighted blanket, when given by choice (not everybody likes the feeling of being even lightly restrained), mimics a hug and increases the production of oxytocin (a feel good hormone), and decreases the production of cortisol (a stress hormone). As an added bonus, it can help relieve symtoms of certain sleep disorders and illness like fibromyalgia and restless leg syndrome!