I bought my first bottle several years ago, I couldn't get the pump to work properly and I found it difficult to distribute it in my hair. Disappointed, I let it sit on the bathroom shelf for several years and used other dry shampoos instead. In sheer desperation, I had to use this again several months ago, and I haven't used any other dry shampoo since then.
By turning it upside down 2-3 times beforehand, it works to pump it out into the hair. The first 2 pumps usually dispense more product, so I keep it a little at a distance to then distribute it a bit more evenly with my fingers in the hair.
The product itself I think is fantastic, it holds the result for a long time and feels barely there in the hair. If you take a lot, it gets a bit stiffer at first, but after a couple of minutes, you can hardly feel it in the hair.
My hair usually starts to look a bit greasier on day 2-3 after washing. I usually put it in my hair in the morning on day 2 or 3. I think it works best when you apply it just before or when the hair is just starting to get greasy, then it also requires less product. I've managed to make my hair look freshly washed for +2 days after using it and haven't needed to "top up".
I also find that it is economical! Spray dry shampoos last me a maximum of a month, but this one has lasted me over 3 months. I'm buying my 3rd one now!
It doesn't get the last star because of the container, who thought it was a good idea to have a spray pump for powder??? It would have been 5 stars if it had a container like Schwarzkopf Professional OSiS+ Dust It.