Ibogaine. Yes it works to cure adictions, and yes it can kill you due to impacts on the heart. Fully healthy people with no known heart conditions do drop dead occasionally while using Ibogain. Also you might have the worst trip of your life, like dragged down by a demon into hell style, or you might see the blessed virgin and be bathed in rainbows and forgiveness and come out a new person. You never know.
Generally more people have positive experiences and outcomes than negative in a clinical/therapeutic setting. Is it worth the risk? That's up to you.
In-depth scientific review of Ibogaine and cardiac risk: https://pmc.ncbi.nlm.nih.gov/articles/PMC4382526/
Erowid experience vault: https://www.erowid.org/experiences/subs/exp_Ibogaine.shtml