I agree with the other posters, I don't think you need to find a food with the spray in it, I just think you should switch him to a higher quality food.
I fed my cats Royal Canin for years and they seemed fine, I didn't think too much of it, but they did shed a lot. I just assumed that it was because they were getting older and they are cats and cats shed. Well when I started researching what type of food to put our puppy on I decided I would put the cats on a higher quality food (I found out that RC wasn't as good as I had thought it was). At any rate, I switched them to Fromm Four Star and their shedding almost stopped. It was like a night and day difference. It probably took about a month for it to work, but all of a sudden one day I noticed that when I pet them I wasn't getting a handful of fur. I really didn't think I would see any noticable difference by switching them so I wasn't looking for a change, but it was so obvious I couldn't not notice.
Check out the Dog Food Analysis website. You can find out everything you ever wanted to know about commerical dog food and then some. Try at least a 4 star food and see what happens. RC is pricey enough that you shouldn't really have to worry about an increase in price by switching to a higher quality food either. You might have to try a few to find the "right" one for your dog, but when you do find it you'll know. No upset tummies, not a lot of waste, firm poops, nice soft shiny thick coat. It will take 1-2 months for you to really notice the change in coat and frequently they will shed their old coat before the new one grows in so they actually might shed more for the first couple weeks.
Good Luck!