Smashbox Anti-Shine may be quite difficult to use but once you handle the technique of application the product will turn out to be a godsend for oily skin on hot and/or humid summer days.
When I first used it the primer was too thich and dense and rather hard to distribute. I waited, as instructed, for 30 seconds and applied foundation. This was a really tough job. The foundation just wouldn't go on smoothly, it just clung to the primer and looked very patchy. But it must be said that the finish I received was satiny matte. Exactly what I needed.
Then I started researching the product and found a review where someone gave some hints as to how to make this primer work and that was it! It turns out you need to squeeze a bit of the product onto your hand and then warm it up by rubbing it against your hand in circular motions. The thick paste turns into something rather watery and clear. Then you need to apply it quickly cause it sets really fast. And you use it only where needed, like your forehead, nose and chin, not all over your face. Then wait for much longer than 30s and the primer will dry completely and leave smooth, non-sticky finish which doesn't make applying foundation hard.
On really hot and humid days the primer works for just a couple of hours, still better than nothing. In moderate weather it prevents shine for much longer hours. This is the product which works best on my oily skin out of all mattifying products I've used so far.
When reading the reviews I learned that it clogs the pores and causes breakouts, I think this is highly possible if you apply the primer straight from the tube. Also don't use it all over, just where you need it. I haven't experienced anything unpleasant using this primer and it certainly did prevent my face from looking more oily than it normally does.
Disclaimer: I bought the product myself for my personal use and I am not affiliated with any company. I am not paid to do this review and everything I said here is my genuine opinion.