Question: In my open-space office our 5-man team, "A" sits next to 8-man team "B". About 3 weeks ago, a colleague from HR came and asked team "B" to mind their behaviour because they were rather loud and tended to swear quite a bit.

In order to accommodate quickly, they decided that for each curse one has to throw some change into a jar. Their method proved effective, as they control each other strictly.

About a week later, they suggested that our team join their "jar fund" and everyone except me agreed to do so. It is not a matter of the insignificant fine amount, but rather that I do not wish to be monitored in such a manner, despite the fact that I hardly ever swear (definitely the least of them all). I explained why I wouldn't take part and deemed this issue settled.

However, one team "B" member keeps nagging me about paying the fine for my grand total of 2 curses (something silly like "damn," no less) basically every day and completely ignores the fact that I'm not taking part. I clearly let him know multiple times that he's being annoying but he doesn't seem to care. At this point, I've definitely ran out of patience and will probably get very unpleasant very soon.

Generally, I would not hold back but I don't want to perform a full-fledged rant at work.

I could notify his superior, but I would rather deal with it personally. To make it clear: I no longer care about having a good relationship with that person, but I don't want to be "that guy" who reports others for generally insignificant reasons.

What is the best way to handle this situation?

**Update:**

So it turns out that the problem fixed itself as the nagging coworker received a notice due to multiple complaints from the client regarding his lack of commitment and work ethic and was allowed to leave immediately.

Answer: 
Tell him you don’t carry change.

The last thing you want to do is play games - like bringing in your own “nag” jar. It only reinforces the confrontation.

Keep it professional, even if they don’t. Tell him you don’t have any change and you’re not playing his game. Then just stop responding, and get back to work.

Consider this: if you were to go to your manager over this, and asked him/her how to properly handle the issue, do you think he/she would say “Take it one step further. Bring in your own jar, label it ‘nag’, and set it on your desk.” Or would he/she say “just ignore them.”
We're all being monitored whether we like it or not. You choose not to participate. That's your prerogative, but you should have anticipated some consequences.

Usually, people nag like this because the noticed that it bothers you. You showed him that this gets to you, so he keeps doing it. Taking other action could make it worse. 

You decided to go this route, so I suggest you work very hard on ignoring this person and demonstrating to everyone else, in some other way, that you are a team player. Maybe you could suggest that a fine should be paid for any type of annoying behavior. Eventually, he'll look like a fool for his behavior especially in an open environment.