If the water coming from the VistaPure wand has a foul smell, potentially like "rotten eggs", the most common cause is near-expired deionization filters.
The composites inside the deionization filters wear down over time and can produce a foul smell when they're near the end of their life cycle.
It is important to replace the deionization filters as soon as possible so VistaPure can continue producing the high quality water necessary to operate autoclaves and sterilizers.
How to Change VistaPure Filters