I just found maybe a bit easier and reliable way to do this.

I updated SCT and SCTD yesterday from wowace so can only talk about version that are at least that old.

Type /sct menu in wow
Go to SCT Custom Events section
Click New Event
Give whatever name you want for the event
At Display type in: *4 (*1)
That will make it look like your damage on main
At Search type in: Shock
Set Event Type to Damage
Set Target to Anyone
Set Source to Friends
Set Event Frame to SCTD
Tick in Show Icon
Click Save Event

Now if your clones are in same guild or on your friend list you will get their Shocks and displayed on SCTD.

Huge problem with this is, if your main is in a guild and guildies are around you shocking you will see their damage too.
Obviously create new event and instead of Shock use Lightning, and you will see all Lightning Bolt and Chain Lightning damage from clones too.

EDIT: Ahh NM, Friend apparently means the whole horde faction :S
Would be nice if it could filter by Character name instead of Spell name tho.