Saccharomyces boulardii is a yeast, which is a type of fungus. Saccharomyces boulardii was previously identified as a unique species of yeast, but is now believed to be a strain of Saccharomyces cerevisiae (baker’s yeast). Saccharomyces boulardii is used as medicine.
Thus, even a small residue of this yeast remaining will ferment formulations. Thus I would recommend the use of an extremely effective fungicide in the cleaning procedure.