There are other TGA approved products such as medication, patches, gum, lozenges, mouth spray and inhalators that can be used as quitting aids
Inhaling Vapor Into Lungs There will not be enough dense vapor in the mouth to produce the O's if the vapor is inhaled into the lungs
Except it wasn't as smoke-free as you would expect
Approximately 50% of all individuals currently smoking had vaped at least once, with this proportion increasing to 60% among those with any psychological distress, indicating that dual use of smoking and vaping was especially common among individuals with moderate or serious psychological distress
While it may be found in e-liquids made elsewhere, diacetyl is prohibited as an ingredient for UK-made e-liquids, and the Tobacco and Related Products Regulations (TRPR) and Tobacco Products Directive (TPD) as it's known to be harmful when inhaled in large quantities