Yes indeed. Us greybeards were tunneling ssh through DNS using a Perl-based hacking tool thrown together by Dan Kaminsky in 2004 called “OzymanDNS”. DNS tunneling is now ubiquitously used for data exfiltration and consequently all major DNS platforms have methods to detect it.

Mind you, this was before the age of WiFi on airplanes. But within other gated networks, it used to work quite well. I recall getting tens of Kbps.