Yeah, I know it's anecdotal... but when I've had issues with people that "stuck", and didn't go away on their own, I've had a lot of success writing those people a letter. It forces me to present all the information factually, how I feel about it, why I feel that way, etc. which helps elucidate the charitable and less-charitable interpretations of what happened. In writing, I have to reread and edit what I wrote a dozen times at least to make it nice and coherent. I also have a rule, that I can't send out such letters until the next day after writing the letter. Every time I've done that, I didn't need to send the letter after I wrote it. The anger was gone. Sometimes it persisted for weeks leading up to me writing the letter.

I would absolutely describe that as "venting". I just wouldn't describe it as super aggressive or hostile, even though sometimes I think the letters were pretty harsh.