This was a new one to me. The Los Angeles Times “Booster Shots” blog reports, “Some parents, hoping to avoid giving their kids the chickenpox vaccine, were arranging through Facebook to pay strangers to send them “[licked] lollipops, spit, or other items,” from kids with the illness.” Infectious expert Dr. Wilbert Mason said this was a “stupid” idea, pointing out that transmission of chickenpox is extremely unlikely through spit, while more “resilient” and “dangerous” infections, such as “hepatitis B, group A strep, and staph germs,” could be spread in that way.
“Jerry Martin, a US attorney for the Middle District of Tennessee, issued a warning that sending chickenpox through the mail was illegal.”
What makes more sense is just getting your kids immunized against chickenpox. You can learn more about the vaccine here.