What is the use case for this?
If I understand things correctly it might be better in your case to unload and load the entire collection, if you are restarting the level for instance.
If you really need to hide the spawned particles immediately you can try setting the emitted particle's alpha to zero with something like:
particlefx.set_constant("#particlefx", "emitter", "tint", vmath.vector4(1,1,1,0))
In this example
tint is defined in the default particlefx.material file.