Since judgement aint on a GCD with your seals, you can use:
#showtooltip Judgement
/cast Seal of Righteous
/cast [target=focustarget] Judgement

That SHOULD work, however, untested.
Setting #showtooltip Judgement, will show Judgement's CD Hope It helped. And hope it worked

I use a macro on my pala for seal of justice which is:
/cast Seal of Justice
/cast Judgement

* That's not for multiboxing though.