This is a pretty awesome idea... If you want your kid to have issues.
I was born on halloween so I always had costume birthday parties. I think it was my 10th birthday, my step dad had shot a deer that morning and it was hanging up in the basement gutted and skinned from the rafters in the middle of the room.
A friend got sent downstairs to grab something, and couldn't find the light switch. He ended up walking blind in to this skinned body. He came running up stairs screaming, then started to cry... I couldn't help but laugh at him for being a pussy... We had to call his dad to pick him up, he couldnt get over it. Never came to my house again.
I probably would have found the humour in the clown... It would be great to pull on a tough know it all teenager! Love seein those kids cry.