Vinegar does not clean urine of methamphetamine traces, and is simply an urban myth. The only way to ensure that your system is free from meth traces is to not take it in the first place.
Amount used
This is an obvious factor, but the amount of meth used will determine how long it stays in your system for. This can increase your likelihood of failing a drugs test even weeks after ingestion.
Age
The older you are, the slower your metabolism is likely to be, and this can dramatically effect the meth elimination process. If you're a younger person, you'll likely be free from meth traces much more quickly.
How healthy you are
A very healthy person is more likely to be able to eliminate meth traces from the body more quickly than someone with poor health.
As mentioned earlier, the best way to clean your urine of meth is to not take it in the first place. It's an extremely dangerous drug, and you should seek help if you're struggling to stay clean.
Here's a video documenting the awful effects meth can have on a person's appearance:
