You could certainly try it, but I would also suggest supplementing it with something like this:
To implant “good” thoughts into your ex’s mind.
Additionally you might want to check out the “revision” technique of Law of Assumption. Google “Neville Goddard revision” and you should find something to point you in the right direction.
You could ask Bael to make your ex invisible to other people, but there may be other rituals that are helpful there too. There’s a ritual in Practical Djinn Magick to make someone unpopular. Or you could, idk, ask a lust demon to remove her aura of attractiveness or something.
Yes it is lol. It might not be mandatory but I’ve included it each time I’ve used this ritual because I am serious about getting the outcome I need. And it has worked each time. Could definitely try it without blood.