The problem is that the most accessible suicide methods aren't exactly the most ideal ones at least to me. Hanging sounds risky, drowning sounds unbearable and like it would be so difficult to succeed with. I think that if there were very accessible painless methods I would be long gone at this point, sadly there are just no easy answers to this as after all we exist in this anti suicide society that restricts painless suicide method options.
With questions like this, all that anyone can do is do their own research, what is the best method for the individual depends on accessibility and personal preference and you cannot expect other people to decide for you, it has to be a personal decision. But anyway, best wishes.