Mental rehearsal has reasonable support as a performance technique, and its trading use is narrow and practical: rehearse the moments where you historically fail. Being stopped out on the open. A gap against a swing position. A winner giving back half. The release of a scheduled number.
Rehearse the full sequence including the feeling, not a highlight reel of success. The point is to have a prepared response to discomfort, which is what makes an implementation-intention fire when it is needed.
Simulation and replay do the same job with more fidelity. Use visualisation for the situations you cannot easily reproduce and replay for the ones you can.
Related: implementation-intention, deliberate-practice, pre-market-routine, performance-anxiety