If you get the choice of Healing vs Killing wrong, this is not going to make a big difference or nullify your treatment. Of all things considered, finding the right frequency is the most important thing.
As for different types of Contact treatment, just find the one that is most convenient for you. You want to if possible run the contact on the High PWR port of the Spooky Boost. Also, it helps to have a carrier frequency over 1 MHz if possible. See this page for how to do this: http://www.spooky2tools.com/dynamic-carrier-for-contact/
For more details, please check the link: