Yes, Sandman, this is actually the best way because now you know the audience is really paying attention and is moved to sing along. Another way sometimes is to stop the accompaniment altogether and gesture to the audience. Some R and B groups will just sing accappella for a moment and indicate hand claps for the audience to join in. The element of surprise is often useful to draw attention suddenly by reaching out to an audience physically with a hand motion.
Pete was a master at this. He could often bring in an audience by playing and singing very softly. Because of his control of the dynamic range of the banjo, he could play very softy and rhythmically and induce a singing audience. Othertimes, while holding the banjo he would outstretch both arms at a climactic moment and the surprise element would result in his leading a chorus from the audience. He was the best song leader I ever knew. Without the dynamic range of his style of banjo playing, this would be impossible.

There is also a beat on the whamming style that resembles a basic rhythm pattern by a dance band drummer. The Weavers used this pattern to get the audience to clap along in rhythm. This was a custom in the early days of the "hootenanny" and employed by R and B, rock and gospel groups.

Pete told me that when he sings a gospel number he envisions himself in a black church.

Pete's style fit in with other instruments that played all styles of music. He could have fit in with rock musicians and earlier jazz musicians.