I do it all the time!
By the time I biuld the intelligence agency, I've already switched to communism, so my spies are veterans. So I have more success planting spies. Then, because I can't cash rush, I tend to have a lot of money, 30k or more. And what to do with all that? Propaganda.
First, wait for two civs to be at war. They'll be usually democrats, so I can't use propaganda on them. But as war goes on, they'll try to switch to monarchy or fascism, if they have researched it. I keep an eye on them to see when they're in anarchy. And when they do...
That's when they will be more vulnerable. Some of their conquered cities will be starving to prevent disorder and will have very little population. A progaganda mission on a size 1 city will cost less than 200g. Anarchists, their courthouses destroyed, no culture, and citizens unhappy. The perfect candidates to flip to my side. What could be better than seeing two civs fight, they take the damage and I steal the spoils?