The couple are keeping their decision to themselves but Tom told the paper that the simplest way is to use an 'exit' bag and to immerse the person in an oxygen-free environment.
He (Tom Curran) said: "It's very quick and pain-free. Within three breaths the person loses consciousness. It's like going to sleep and then within 15 or 20 minutes they are dead as they are deprived of oxygen."
Marie has confirmed that she will decide to go if she gets locked-in syndrome, or if she can't talk or listen or see.
Flagging the 'Exit Bag' option flies in the face of the entire thrust of Marie Fleming's court case. To use this approach she would need assistance. Assuming that such assistance came from Tom Curran (or anyone else for that matter) they would risk falling foul of the law.
Of course, that is, unless the method is undetectable at autopsy. This 'undetectability' is the main marketing slogan for Dr Nitschke and his nitrogen death method marketed through his company 'Max Dog Brewing'. The presence of nitrogen in the blood is normal - there would be no test that could determine a cause of death by this method.
Of course, to be truly undetectable still requires the removal of the paraphernalia post-mortem; in other words, the involvement of a third party.
This is where the Max Dog option is exceedingly dangerous. It could easily be purchased by a malevolent relative or carer to dispose of an elderly relative. Max Dog supports the risk of Elder Abuse.