Quote: "That explains why nothing was working properly when I tried altering the decal-particle script. Thanks Maho, guess I'll have to pull out some modelling tricks on this one."
One option would be to build your effect into your model, rather than fooliing with the particles.
When building a rocket, I opted to make the exhaust as a seperate part of the model.
I animated it to be hidden in the rocket when idle and pop out when thrust was applied. (2 animations)
I rotated that piece really fast, and shaped it in a way that gave a nice effect.
It wasn't perfect, but it did the trick, and it was not difficult at all to pull off.
Doing it that way is totally controllable by the scripts.