According to the National Museum of American History, Halo Shampoo was still being sold in the 70s. However, the "zero-soap" shampoo, which was introduced in 1938 by the Colgate-Palmolive-Peet Company, is no longer sold in the U.S. The vintage shampoo was made popular during the 40s by its jingle, "Halo, Everybody, Halo," a song that was initially played over the radio.
Halo Shampoo, which provided a double-back money guarantee, was promoted by a number of celebrities in the 40s and 50s, including Frank Sinatra, Eddie Cantor and Peggy Lee, each of whom sang the Halo Shampoo jingle. The shampoo's famous slogan was, "Soaping dulls hair, while Halo glorifies it."
According to Retro Scoop, Colgate launched a publicity campaign for the product in the U.S in 1955. The campaign consisted of working with record producers to boost sales in the teenage marketplace.
The Halo jingle was sung over various radio stations by such artists as the Fontane Sisters, Sunny Gale and Mary Rose Bruce. The National Museum of American History says that ads featured in 1956 claimed that Halo was "America's #1 selling shampoo." According to the Museum, the shampoo was touted as being clean-rinsing and safe for children because it didn't contain oils, harsh chemicals or soap.