I've been looking into drinking a large amount of alcohol and then drowning in my tub or in a lake near my house so that I will be unconscious before SI kicks in and I won't feel an intense amount of pain. While I was looking at statistics, I saw that it was not as common as a method when compared to hanging, jumping off of something, or taking poison/overdose. I'm just wondering why this method is not used as often compared to other methods.
I would say that it has mostly to do with the reduction of suffering.
When you hang yourself, one of 2 things happens, or both :
1. Your carotid artery is compressed, you pass out, ez. 2. Your neck is snapped, ez.
No real suffering involved.
Jumping off a high place is probably scary for a moment, but when it's high enough, a relatively quick death is guaranteed.
Poisoning and overdoses are in general bad ideas, unless you know exactly what you're taking and in what effective dose, otherwise you'll just ruin your liver and have a very very bad time.
The thing about drowning is that it takes a good while. Not only that, but discomfort will definitely be there, cold water for example, or strong currents that crash you against things, or maybe pull you down and spin you around. When the actual water inhalation starts, it will probably be painful, a struggle for air, survival instinct. At some point it will be peaceful of course, but i'd say that drowning is not as common because of these factors.