Some of the additives I tested would probably classify as "odorless", others smell like a paint factory.
Skiddins- As I understand it, the "tire wash" is to remove the treatment from the tire, without drying it out, probably between events. I haven't tried it, just used the clear stuff [HT Series 1] to clean tires, gets rubber build-up off the tread quick, fast, and in a hurry!
I'm interested to see how these preps work on asphalt as well.
Also, I think I need to correct an earlier statement: New scuffed tires are still faster than used tires, but the additives we tried on used tires dropped about .2/lap compared to the regular additive we had been using. As pleased as I've been with the sauces I've tried, it's not magic, but it has helped to get a few more competitive runs out of a set of tires.