Knocking, rapping, tapping on the body of string instruments

Hello,

I ask your help to know how to write these contemporary string techniques (knocking, rapping, tapping on the body of the instrument either with one’s fingers or knuckles) in Dorico.

Thank you

Usually I find these written as x-noteheads.
One can “Suppress Playback” in the Properties menu or assign the knocks/taps to a separate voice and associate that voice with an appropriate sound (VST channel) in Play mode.