Can you put vape juice on a cigarette?

It is absolutely forbidden to drip or apply e-liquid onto traditional cigarettes and then light them up for smoking. This is an extremely dangerous and harmful behavior.
This is not a simple "mixing", but it will lead to highly toxic and risky consequences. The main hazards are as follows:
⚠️ Two major core dangers
Chemical hazard: Generation of highly toxic substances
The e-liquid is not heat-resistant for combustion: The e-liquid (mainly composed of propylene glycol, vegetable glycerin, and fragrance) is designed to be atomized at relatively low temperatures (usually around 200°C). In contrast, when traditional cigarettes are burning, the center temperature can reach over 800°C.
Production of toxic aldehydes: Under such extremely high-temperature and incomplete combustion conditions, the components in the smoke oil will undergo decomposition, generating a large amount of formaldehyde, acetaldehyde, propylene glycol, and other highly toxic and carcinogenic aldehyde substances. The concentration of these substances will be much higher than that in normal e-cigarette or cigarette smoking, causing strong irritation to the respiratory tract and eyes, and seriously damaging lung cells.
Physical hazards: Uncontrolled combustion and poisoning risks
Uncontrolled combustion: Propylene glycol and glycerin in the smoke oil are flammable substances. Applying them to cigarettes may cause abnormal flames, uneven combustion, and even "sparkling" splashes, which could lead to a fire.
Nicotine poisoning: If the e-liquid used contains nicotine, when inhaled through high-temperature combustion, the amount and rate of intake may be much higher than when using an electronic cigarette or smoking normally. This can cause rapid heartbeat, dizziness, nausea, and even acute nicotine poisoning within a short period of time.
Poor experience: Besides being toxic, its taste is also extremely unpleasant. There may be a strong chemical odor and a harsh irritating sensation in the throat.
Summary: These are two completely different products.
Please make sure to understand the fundamental differences between electronic cigarettes and traditional cigarettes:
E-cigarettes: By heating the vaporizing liquid, aerosol (non-combustion) is produced.
Traditional cigarettes: By lighting and burning the tobacco, smoke (containing thousands of chemical substances including tar) is produced.
Mixing the two together means combining the risks of both sides and creating a new and more dangerous chemical reaction. There is no safe or reasonable reason to do so.
If you or someone you know is considering or attempting this method, please stop immediately. The health risks are immediate and severe. If you are dependent on nicotine, seeking a safer and more controllable alternative (such as a regulated nicotine replacement therapy) or consulting a professional doctor is the correct approach.