My own take is that I don't want to interfere with the tire's chemistry by using strong cleaners or tire dressings that will disolve into the rubber. And acidic/alkaline or even worse fluorinated cleaners just seem like a bad idea.
The tire is supposed to leach brown stuff over its lifetime as the anti-ozone chemicals work their way to the surface.
The only tire care products I would use are
Tire Care Products: Tire Care & Buying Guide: Michelin Tires
But they don't have those in my area. I have used Turtle Wax F21, and it seems to get the tires pretty clean, though you do need to scrub the rims to road grime/brake dust off.
The tire is supposed to leach brown stuff over its lifetime as the anti-ozone chemicals work their way to the surface.
The only tire care products I would use are
Tire Care Products: Tire Care & Buying Guide: Michelin Tires
But they don't have those in my area. I have used Turtle Wax F21, and it seems to get the tires pretty clean, though you do need to scrub the rims to road grime/brake dust off.