Canon 630EXRT w/ 430EXII as slave

Ive just had a quick look through the forum here and couldnt find anything on this, but I was wondering if it is possible to utilise 430EXII as a slave, triggered via a 630EXRT, which in turn is being triggered via a Canon ST-E3-RT?

Ive tried it out myself and cant seem to get the 430EXII to fire although I have not spent too much time troubleshooting as yet.

Any tips or suggestions?

Can't be done the way you're trying. The 600 on camera can trigger the 430, or an ST-E2 could trigger both (but not the ST-E3 which is RF only).

Cheapest way to do what you want is to get a Sonia green optical slave trigger for the 430 (flashzebra.com).

Cheers for the heads up - i will look into it!