Dichlor does have CYA (stabilizer) in it. It adds 10ppm of CYA for every 9ppm of chlorine it adds. So, it will raise your CYA quickly! You won't want to use it for long and then you can switch to bleach.

(It also is very acidic and will drive your pH down, so keep an eye on it so it doesn't go below 7.0.)