There's 2 very different kind of placeables:
While it is a simple “checkbox” in the placeable properties, it changes a lot of things.
To add Visual Effects to a placeable object, set it to non-static (dynamic), set the placeable OnHeartbeat script to “plcvfx_self” and add integer var PLCVFX_SELF, (or PLCVFX_SELF1, PLCVFX_SELF2, PLCVFX_SELF3, etc) with the desired VFX index number(s).