The booming bass voice of Paul Kallinger was used to sell many of the products on XERF. At night, his recorded spots between the different sponsored shows served as a jingle break. Kallinger remained on the Texas side of the border and recorded his spots at a studio in Del Rio, because he did not want to become embroiled with the lawlessness that swirled around the XERF studio and transmitter on the other side of the border. In between the different religious programs, Kallinger would tell XERF listeners in various versions that: