Vinegar is a good bug killer, but so is wine. Anything that could live in wine can probably live in vinegar, including the bacteria that make wine into vinegar. Now, there is nothing alive in vinegar you can buy at wal-mart. But those bacteria are around and vinegar won't kill them.
More and more I'm using iodophor. Used properly (12.5 ppm solution in contact for one minute, reuse while still ice tea colored), it is effective, no rinse, and cheap. I've just started in wine making, but it also sounds like your KMeta should be used as a disinfectant, since it degrades too quickly, and you use such little quantities, that it isn't worth it to try and save it too long.