Like ammonia I would stay away from vinegar as its an acid, if you buy a gallon of automotive windshield wash you'll have it covered many are ammonia free, I really want to try the Rain-Ex stuff but don't want to be the guinea pig my thinking is its got a really good surfactant quality once on your windshield water just beads right off I was thinking this would be good plus it might help with tip dry if the paint can't stick to the needle it can't build up thus no tip dry, right