You could always just use a variable to check whether the clown is alive or dead, and if they're dead, have the other passages automatically redirect somewhere else. At some point prior to meeting the clown, such as the beginning of the story, set the clown variable to "alive" (while first making sure that the clown hasn't been killed yet, just to make sure that you're not unintentionally bringing them back to life if revisiting this passage later).
(unless: $clown is "dead")[(set: $clown to "alive")]
Then, after you kill the clown, set the variable to "dead".
(set: $clown to "dead")
Finally, in the passages where you would interact with the clown were they still alive, set a go-to to activate if the variable is set to "dead". This will cause it to automatically load the specified passage before the clown interaction is even displayed.
(if: $clown is "dead")[(go-to: "PassageName")]
This way, so long as the clown is alive, the player can access these passages, but when the clown has been killed, the game will never display them. Is that along the lines of what you were looking for?