Yes, we are familiar with it.
No, you shouldn't use it -- it won't do ANYTHING to solve your current problem.

The fact that several days ago your chlorine went to 1 ppm in just an hour after a large dose tells me you have a VERY high chlorine demand, most likely from ammonia. Please read this page:
spring-swimming-pool-startup-problems.html

It's possible to have NO stabilizer (so you lose chlorine during the day) AND ammonia (so you lose chlorine day AND night).

Draining 100% and refilling is an option.
Draining 50% will remove 50% of the ammonia

If you don't remove it all, you'll have to add bleach till you destroy all the ammonia gone. Since I don't know how much ammonia you have, I don't know how much more bleach it will take.

But, if you aren't going to drain, do like Carl says, and add larger doses at night. Once you see high chlorine in the morning, you are close to being done.

Ben