This is another diy I've been using on my baby that has worked beautifully. Why should you think about making your own diaper rash cream you ask? Because this way it can be fresh and pure every time!
I would like to start off by saying that diaper rashes are a part of babyhood, and some babies get more rashes than others. My daughter was super good at keeping diaper rashes at bay until she started eating more of a variety of fruits. Once the potty training kicks in, food limitations won't be as much of an issue, but until then, we had to temporarily eliminate strawberries, raspberries and tomatoes from the menu since we noticed they would cause diaper rashes no matter what we did to avoid them (due to the acidity I suppose), once we removed those foods, the rash was gone. All this to say, that no cream will help an underlying cause if no changes are made. If your child has a very stubborn rash that won't go away, don't focus on a barrier, focus on making the internal changes (most likely dietary) by the process of eliminating and re introducing foods you suspect are causing the issue.
Most commercial products will contain water as a main ingredient (first ingredient listed on the ingredients list) because it's cheap and cuts the production cost of the product per gram to maximize profits and while there's absolutely nothing wrong with water/aqua, preservatives will automatically be needed to stop that same water ingredient from creating an infestation of bacteria over time in the product. Any company that says they use an all natural EFFECTIVE ingredient as a preservative is full of s*#t... I'm not saying synthetic preservatives are lethal and should be avoided at all costs since they are needed in products containing water to keep them safe, but if you can find a way to omit them, many people would love to since they do take away from the purity of a product, and why pay a high price for something that isn't even pure? Just know that anyone using water in their products and NOT using a potent broad spectrum preservative (and only using something like rosemary, grapefruit extract, vitamin e, etc...) is selling you a ticking time bomb of bacteria so stay away from it...The only negative to making your own natural products is that it can't sit on a shelf for crazy amounts of time, but why would you want that anyways? I feel like the fresher the better! Plus this is the type of product many parents will use extremely often in their babies early years so the more natural the better in my opinion.