Very good advice. I just used it to capture another province on Kyushu when it was captured by a moderately powerful "friend" of mine. Without it, I wouldn't have been able to capture the Very Fertile province next door. Thanks!
However, a word of caution about using it during the early stages of the game. The rebel army spawned can be really big - in my case 6 sabre cavalry and 10 levy infantry were spawned. The also reduced the town wealth of the province to zero. I was running around my Daimyo, plus 6 spear levy, 3 line infantry and 2 levy infantry. I had to siege and wait for them to sally forth in order to take the city. It helped that I assassinated the rebel general beforehand
