I studied mechanical engineering and only have a basic knowledge of chemistry, so please take this as just a diary of experience rather than pure fact, what I understand is that the combination of oils and solvents in LW, WD40 and PB Blaster, penetrates the tire and makes it softer and stickier. Same is basically true for most of the tire sauce compounds available.

To really analyze how this works we'd need to know the exact chemical makeup and processing behind each brand of tire as well as the exact chemical makeup of the sauces to really understand how it works. Most "rubber" is at least partially synthetic.

Hope that helps....