2007 Toyota Camry Fuel Injactor

Cleaned the Fuel injector at Bouche Services and now I have to crank twice before the engine starts, I was told by the Bouche Mechanic that it is normal since they cleaned the fuel injector and I have to wait for about a week until Carbon builds up on them again for it to start normal. Wonder if this is correct or not, by the way my fuel pump is one month old only so it works fine.