Green’s Dictionary of Slang

chew the rag v.

also chaw the rag
[rag n.1 (3a); orig. use held overtones of grumbling and complaining, but this vanished by the 1920s]
[late 19C+] (US)

1. to gossip, to chatter; thus rag chewing n.

2. to grumble, to complain.

3. to argue, to speak irresponsibly.