That's a crazy method lol. I guess it works, but the spam could be annoying. I honestly wouldn't use that unless chaterbox was the last achievement I had to earn and I was trying to get all the achievements.
If you are trying to collect all the achievements, I'd honestly ignore chatterbox. By the time you complete all the other achievements, you probably would have already crossed the needed posts to get chatterbox normally and then you aren't spending "extra" time trying to get it.
To get this achievement, you have to earn social points ( if you don't know what this is click on this https://www.chess.com/blog/Nevisaurus_Rex/activity-based-achievements) Basically, you have to get 10000 social points and THE MOST EFFICIENT AND EFFECTIVE WAY is to create a club and post an unholy amount of announcements. If you already have a club, create a second one because your members are going to go crazy. Then spam news (one letter announcements are OP for this) and repeat until you get it.