"Joe, you have an unpleasant body odor. Now sometimes it can be a medical condition which scammer is why I'm talking to you about it It's not necessary to go into the discomfort it causes everyone else. It's obvious, otherwise he wouldn't be meeting with you. And to mention others at this point would make Joe more uncomfortable.
There are various chronic diseases which can also lead to bad breath as well. Various lung diseases or liver diseases, for example, can cause bad breath. And that isn't all the medical conditions that you could be suffering from that can cause halitosis some of which you may not even know medicals fake you have.
With medicals bad and fake the news out there it can't be taken back. The only thing you CAN do, though, is maintain a level of dignity for "Joe" by assuring him that the discussion is just between the two of you.
On that note, check your emotional baggage before you leave the house. The first date is not the night to talk about your cheating or alcoholic ex, manic depressive parents and troubled childhood. You shouldn't be bogus, but you can save these topics for later dates when it looks like you're growing closer together. First impressions count and you don't want her to identify you with negativity on your first outing.
If you're lucky, these products will do nothing at all. Some of them are seriously dangerous by themselves. They promise cures for life threatening illnesses, causing those who buy the promise to delay proper medical treatment, sometimes past the point where it would have helped.
Disclaimer: This article is based on information freely available in the popular press and medical journals that deal with health. Nothing herein is intended to be or should be construed to be any sort of medical advice. For medical advice the reader should consult with his or her physician or other medical specialist.