How long do the effects of square jaw Botox last?

Every time I look in the mirror, the masticatory muscles on both sides of my jaw seem to bulge out, so after much deliberation, I am looking into a procedure.
My jaw muscles tend to feel tight when I chew food, so I am thinking of getting a consultation.
People around me have recommended that square jaw Botox is quite effective for those with a muscular lower face.
However, I am curious how many days it usually takes for the lines to become noticeably defined after actually getting the injection.
There is also a saying that you have to wait about a month for Botox to work on muscle reduction to achieve the slimmest result, and
I also saw reviews saying that the peak is in the second month because the response speed varies from person to person.
Also, I am curious to hear everyone's experiences regarding how many months the effects of square jaw Botox last, based on your experience.
I've heard that the effects of the medicine wear off quickly if you eat a lot of tough food, but I also want to know if being careful with my diet in daily life definitely makes it last longer.
If anyone has seen results from square jaw Botox in cases like mine where the masseter muscles are well-developed, it would be very helpful if you could share the progress after the procedure or any precautions.