The use of echo-e \"\\ 029\" does not work either. But if use strg + alt gr + ] directly in a terminal session -> it works.
echo-e \"\\ 029\"
To quit telnet on redhat: type "CTRL+5" and then type "quit"
"CTRL+5"
"quit"
Ctrl + ] This will show as ^] and then
Ctrl + ]
telnet> q q is for quit
telnet> q