I just re-read the thread and there's some good info in it (thanks for starting it ScottWolf ). I first started down the "natural ingredients" path when I started shooting black powder muzzleloaders. It is widely accepted that it's a good idea not to use petroleum-based products due to the residue problems with BP. Having said that many swear by Ballistol, which is a German product used widely by their army during WWII. What many don't realise is it's virtually all medicinal-grade mineral oil, with something added (anethole these days) to make it smell nice!
There are as many recipes for patch lubes as there are for leather conditioners! I have spent many hours searching for the MSDS for both, and it isn't always easy to find out what is in them. Regarding leather conditioners probably the most common/widely used ingredient is medicinal/food grade mineral oil as this blends nicely with waxes to make them "spreadable". This is also apparently considered by some manufacturers to be natural. Paraffin wax is also widely used presumably because it is readily available commercially and no doubt is cheaper than using beeswax. As with the mineral oil the wax is basically a highly refined petroleum product.
Some manufacturers don't list what is in their products in the MSDS because if the products are natural and aren't considered dangerous within the various regulatory guidelines then they're not required to list them. Most of them usually have beeswax, because it's a great marketing tool to say it contains beeswax, but you don't know what is used to make the wax "spreadable". I once made a concoction using beeswax and pure gum turpentine as the solvent (natural, you see) but over time the container developed a black tar-like deposit in it so I haven't used it since. I also made my own tallow from sheep fat (suet) using a slow cooker. That was many years ago and I've still got some, it's stored in a shed that gets bloody hot in summer and very cold in winter and it's still fine. I've found extra virgin olive oil works well as a softening agent when mixed with beeswax and so far haven't found any downside to it. Blending waxes is a fascinating exercise.