I have used plain old Kiwi mink oil on my shoes for 30 years. Never had any bad consequences. (This is NOT the Kiwi mink oil with added silicone that is formulated for boots - just regular old Kiwi mink oil). I use it in very small amounts, rub in thoroughly and then buff off before applying creme polish followed by wax. If over applied it can indeed leave your shoes oily and resistant to a good shine - but this will only be temporary and is only true if you really soak the leather.
I have recently started experimenting with Saphir Renovateur. It is indeed a very nice product - creamy and easy to apply - and it creates a shine on it's own (it must have some wax in it).
I notice that the Renovateur also picks up more of the existing finish off the shoe. As when using it over polished shoes I get lots more color on the polish rag than I do with mink oil. This indicates to me that it has a bit more of a solvent in it than regular mink oil. I also applied it to a pair of boots that had been previously mink oiled and it darkened the boots quite a bit.
I believe that when comparing the two that the Reno is being absorbed more deeply into the leather than the mink oil was based on my initial tests and the way the leather on the previously mink oiled boots darkened in spots all over the boot immediately upon application. This darkening is usually indicative of moisture and the spottiness disappeared over the course of a day or so, also indicative of moisture being absorbed into the leather. This darkening had not previously occurred on the very same boots when I had mink oiled them just the week before.
That's it - no conclusions or pronouncements - just some observations.
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