Drain was slow for a couple weeks and I used baking soda and vinegar, which usually works. Then it started bubbling and the kitchen sink wasn’t draining. I swore I had the grey tank open but it was the black tank that was open.
So if it’s bubbling, double check 😉
I’ll one up you. I forgot i was flushing the black tank while doing something else and it over flowed. Caught it right away but that was a fun cleanup.
Source: Learn from my mistake: make sure your grey tank is open when unclogging a drain