I spray it on and let it sit for a couple of minutes. Then wipe with a white shop towel, amazing how much dirt it removes from a clean tire. It lasts OK, I apply after every wash as it doesn't take long.
Also, it doesn't seem to attact dust like some products.
Does Armor all still turn your tires brownish in color if you're not freuqntly applying it? It's been a while since I used the produt (almost 10 years). I found that after a while the tires become brownish in color if your armor all protectant is not constantly used. After some research I found that the color change comes from the type of protectant used (i.e. silicon vs. water-based... something like that). I'll check back at home to see which product I have... it's been a while since I had the chance to hand wash my cars.
I have been using More Shine Less Time for tires from Stoner car care products. Lasts a long time, and gives you a nice natural look, not wet look like other products. Only available in US. Bought some on my last visit to US.
Funny years ago I use autoarmor in my tires... three sets.... each tire as they aged developed light surface cracks. After that car I stopped using it.... I never got surface cracks in the sidwalls again on any tire.
I guess if you like the look but don't do it for protection.... IMHO it does nothing.