I started using the following and it seems to be working:

/castsequence [target=focustarget,exists,nodead][target=target] reset=10 Seal of Righteousness,Judgement

I'm judging Righteousness whenever I am able.

Your macro with:

/castsequence [target=focustarget, nodead, harm][nodead, harm] reset=10 Seal of Righteousness, Judgement

seems interesting. I'm going to give that a try. Thanks a lot!