Maybe it depends on the situation. I know it backfired for me because I was using it on my belief that there was a third party, when in fact it turned out there wasn’t one. Only the potential for her to exist, created by my own thoughts that I wasn’t good enough for my SP. What resulted was that I repelled my SP because I believed he was more interested in someone else than in me. It didn’t move him closer to her, but it did move him further from me.
Then again, I’ve heard it can work really well when you’re clear about what’s being rubbed out, and you’re replacing the void left by what’s been removed with a pure intention of love. I can see how this would work with situations, too, like imagining you’re erasing a rejection letter and replacing it with what you want to read instead.
So it’s essentially revision. I’d say just be sure you aren’t re-creating the thing you’re revising by your belief in its existence, and try to always come from a place of self love — which is really love for all, because there’s no such thing as you/them.