Ok, this might be know from many, but instead of just typing your mqtt publish commands in a terminal, you could use Mqtt Spy!
It’s free, open source, and works pretty well! It allows you not only to subscribe to topics for debugging, but also to publish!
And as a little gift, here are the scripts to publish on Snips/Hermes topics, so you don’t need to type them repeatidly!
You can download the entire directory and let mqtt spy know where they are, once connected to your mqtt server, under scripted publications (right click there ). It includes definitions for Snips Led Control as well