Did you buy the SMooth N Shine Mousse from a pharmacy? If so, I never see the Curl activator gel there. I only know of Beauty Supply stores selling that gel.
Although I never used the curl mousse, I got a refund cause it had (and personally smelled strongly like) alcohol. I didn't wanna chance putting it into my own hair. You may get different results though, I dunno. I used the gel and the other Smooth N Shine mousse (alcohol free..not specifically for curls) together, and it made my hair look nice and bouncy with little shrinkage, however it didn't look as shiny when I used the gel alone (alot more shrinkage).