I think as women we are so communicative, it is incredibly difficult to enact the power within silence. Whereas men, I think, respond so profoundly to effectively ignoring. It is crazy difficult to do too. In emotional moments, I think we all just want to express our point and be done with it, but not saying anything, can truly be the most powerful.
Pro-tip: one archaic way that I go about this, is by opening a note on my phone and typing what I would like to text a guy. This helps me because I am still expressing what I need to express but I can have time to sit on it. If it still feels worth sending in a day or so, I still have it easily accessible, but in the heat of battle it is contained. As a highly emotional creature, I know that I can get too wrapped up in the midst of a spat to think calmly and rationally.
Which don’t get me wrong, I completely support going full “Gone Girl” crazy, if that’s what you need. Sometimes I think it’s downright necessary to let the emotion happen. Oddly, I had a dream about my most heartbreaking ex to date last night. I know that after the breakup with him, I tried so hard to be a “cool girl.” I was so convinced that if I was fun and positive and carefree surely he would beg for me back. That didn’t happen, and I think it delayed the inevitable. After 6 months of drawing out the heartbreak, I finally let a T-Swift-esque flood of emotion via text just pour out. I didn’t get a response, nor did I really want one, but I felt I was only able to heal once I just let it out/go.
I realize I’m giving conflicting info here, but I think it’s situation dependent. If whomever doesn’t deserve your emotion, ignore him. If he took up too much of your time already and you literally have one last thing to get off your chest then no harm in telling him, all the reasons you feel content to say: boy bye.