Break up sour jar for one of the partners

Hello all. I need to break up a couple without harming one of the members. I know spells consisting in a sour jar for both, however I don´t want to run the risk of harming one of thr two members of the couple. So I have thought of this: What about trying a sour jar only intended for the member of the couple I want to kick out? If one of them becomes depressive, unstable, jealous, etc the couple will break.

Let me know, please.

What´s your opinion on this?