If you connect to both outputs of an Eventide stompbox, each output will be half of a stereo pair, so if you use one of them as a send, it will miss part of the signal. But, try it and see.
The pedals don't have any internal routing, beyond that used for Pre/Post or Wet/Dry modes (see UM).
You would normally only use killdry with a parallel effects loop, or an effects send and return from a mixer.
