You can always readjust the dummy model you know...
anyway, I don't think scaling is a problem here... the OP only wants to know how to destroy those effects... he can do so via hashtables and some timed trigger...
Using dummy abilities that adds buff like stormbolt is not a good idea, because if some other ability which uses the same base as our dummy ability is casted upon the unit, their buff will never stack...
Only aura based abilities can stack buffs even if from the same base aura... which is why, custom buff systems [like Anitarf's] rely on the slow aura (because the main aura ability doesn't show on the UI too)