Pennywise could be in the omnitrix. But would Ben turn into him?

And just a question that I always had, actually. I know he's afraid of clowns. Let's suppose he's in a specific situation that only this Alien will solve, could Ben overcome this fear to transform into the alien? The hero has already overcome The Ghost, which is scary as hell, it would be very epic if he overcame his fear of clowns to save his grandfather and his cousin.