Mail them each a coupon for mouthwash and sign the letter, “A Friend Who Cares”.
There is a cop who likes to come in and talk to me at work. His breath never varies…it is always horrible. Really, really bad. Fortunately I can keep the counter between us.
And at my recent class reunion, an old friend came up and hugged me and talked to me for a while…when I returned to my table, the first thing I said was…“Now I know why his wife divorced him…his breath hasn’t changed in ten years.” He does seem to have some dental issues from the look of the teeth I could see. But he works in sales and has more than enough money to get things fixed…I’m baffled as to how he can effectively do his job when people are always backing away from him. Maybe they just agree to buy anything just to get him gone!
[QUOTE=Cat Whisperer;I think the breath mint thing could work, but you have to do it right. “Would you like a breath mint?” “No thanks.” “I think I phrased that wrong - have a breath mint.”[/QUOTE]
Washing teeth? With what? Soap and a sponge?
As for the mints - tell them to take two.
PEEEEEEEEEEEEEEEEEEEEEEYOU!
Subtle, but effective. 
Sorry, I was thinking in Spanish. We don’t “brush our teeth”, we “wash our teeth” or “wash our mouths” (and the pronouns are reflexive, not posessive).