What can actually be used that is safe instead of vape juice?

From a scientific and rigorous perspective, we need to be honest and tell you: No inhalation behavior is absolutely safe. "Safer" or "lower risk" should be the correct perspective when discussing alternative solutions.
Rather than seeking the perfect "safe e-liquid", it would be better to change our perspective and look for alternatives with lower risks. We can categorize them into two main directions: inhalation alternatives and non-inhalation alternatives.
⚠️ Important reminder: All the following discussions are only applicable when no nicotine or CBD or other substances are present.
??️ A relatively low-risk inhalation alternative
If your main goal is to obtain some steam and satisfy your hand or mouth habits, you can try the following options, but be aware of their potential risks.
The top choice for reducing inhalation risks: Herbal Vaporizer
This is a device that completely changes the way of "inhaling". By heating at a low temperature, it turns the effective components of herbal plants into vapor. The biggest difference is that it uses pure plants and does not require any "smoke oil".
Working principle: Simply place dry plants (such as chamomile, lavender, and chamomile flowers, etc., which are herbs) into the device and heat them, thereby generating steam. Since the temperature is much lower than the ignition point, the harmful by-products (such as tar) produced are theoretically much less than those from combustion.
Potential risks: At present, there is a lack of comprehensive research on long-term inhalation of herbal steam, and the source of the plants needs to be strictly controlled to avoid contamination by pesticides or heavy metals.
2. Risks come next, but they are far from harmless: Pure plant glycerin
For users who still wish to maintain behaviors such as "spinning smoke rings", this can be understood as a "simplified version" of the e-liquid solution.
Specific approach: The smoke of e-cigarette oil mainly comes from the mixture of Vegetable Glycerin and Propylene Glycol. Selecting 100% pure, nicotine-free, and fragrance-free vegetable glycerin can minimize the harm caused by chemical additives to the greatest extent.
Potential risk: Even pure vegetable glycerin may decompose and produce harmful substances such as formaldehyde and acrolein when heated to a high temperature.
3. The highest risk and should be avoided: industrial raw materials or water-based substances
There might be so-called "home remedies" circulating online that suggest using water, cooking oil, or other liquids instead of e-liquid. These operations are extremely dangerous. Please do not attempt them at all.
Water: Has an extremely weak ability to generate steam, and may cause burns to the respiratory tract.
Oil: Inhaling lipid substances can lead to exogenous lipoid pneumonia, which is a serious and potentially fatal lung disease.
Alcohol or other organic solvents: Their vapors have a strong irritant and toxic effect on the respiratory tract.
Avoid risks at the root: Non-inhalation alternatives
If you wish to quit the habit of inhaling nicotine while also completely avoiding the risk of inhaling any foreign substances, then the following methods are the better choice.
Drug replacement therapy: Nicotine patches or nicotine gum are currently the most widely used and clinically proven smoking cessation aids worldwide. They release small amounts of nicotine steadily and slowly through the skin or oral mucosa, helping to alleviate withdrawal symptoms.
Behavior substitution: Some healthy habits can be adopted to "replace" the original behavior patterns.
Hand-held or mouth-held items: such as flavored toothpicks, sugar-free chewing gum or hard candies, etc.
Hand activities: You can try playing stress-reducing puzzles, squeezing stress-relieving balls, or immediately getting up and walking around when you feel the urge to smoke.
Professional consultation and psychological support: Seek professional assistance from the smoking cessation clinic, or call the smoking cessation hotline (such as 12320), to receive behavioral guidance and psychological support.
?? Summary and Recommendations
Overall, the most crucial step might be shifting our focus from "what to replace it with" to "why I want to smoke". This can help you think from the root cause, and perhaps enable you to find a more effective solution that truly suits you. If you feel that your personal efforts are limited, seeking help from a professional smoking cessation clinic in time would be a more reliable option.