Note that the product does not have good reviews on Drugstore.com, about 2.5 out of 5 stars with 13 people reviewing it. However, those people were using it to treat their plaque, not their flaky lips.
This product was tested by the official European Food Safety Authority and they note that the company didn't provide them proof of what was in the lozenge and that the lozenge didn't seem to work on the experimental group they tested:
"The Panel concludes that a cause and effect relationship has not been established between
consumption of Gum Periobalance™ tablets and chewing gum and “rebalancing the oral
microflora or improving oral health” in the general population."
4. If you want to try using probiotics directly in your mouth, I would go with the original suggestion of swishing around the probiotic liquid that comes in a big bottle. It's much cheaper (I have found the blueberry flavor on sale for $6.50) and it probably is more effective than this lozenge.
5. Or, you could try a chewable probiotic which is meant to be ground up by the teeth and activated by the saliva before it's swallowed. Some examples: