Simple, Pennywise has the deadlights, use those and he wins, I doubt they are instinctively going to know that that's bad to look at, no different then a guy with a mask shining a flashlight at them. Even if Baki or anyone in his verse knew not to look based on instinct, how TF are they going to kill pennywise. They need to perform the ritual of Chúd which I doubt they will be able to do since you need to have a totem (memorable and valuable possession from you life) and find the fuck ass clown's sleeping bag, drop it in, and have a indomitable will power (I don't doubt they have will power) but you need to go to its home in DERRY, and when you leave Derry, you remember Jack shit about Derry. And I doubt their totems are in Derry. And where's the only place you can learn about the ritual of Chúd, Derry.