Why not follow the manufacturer's instructions?

As I said, the manufacturer's instructions are somewhat incoherent. You're told to repeat the application, but they don't say to do it after ten seconds, or after a day. There are some online who say to wait a day or more between applications. I can see some sense in waiting, because if you flush the whole 2# down the drain, most of it will just get washed past the roots. If the goal is to keep the roots saturated with the stuff for a while, flushing all of it at once isn't going to do that.

I usually assume that little effort is put into writing manufacturer's instructions with clarity, because the assumption is that no one reads them anyway.

Thanks. But it never says that in the instructions, which I have read.

"Add product to sewer lines by pouring about 1/2 pound increments into the toilet bowl nearest the sewer line and flush, repeat this process until the recommended dose has been added, or remove cleanout plug and pour entire recommended quantity directly into the sewer line. Replace the plug and flush the toilet several times."

Just out of curiosity, where does that 2 hours come from?

Also, left unsaid is that it's probably not smart to let the crystals dissolve before flushing. I have to assume that the idea is to get the crystals trapped in the clog, so they release the chemical slowly into it. If the crystals are dissolved, the solution will just flow right through the clog.

I tried. You'll do what you want to do anyway.

Bye!

I'll ask elsewhere. No wisdom here.

Dan,

I think that you want to run the line with a mechanical drain cleaner. I think that's the only reputable way to remove roots.

@User - You aren't wrong... but a mechanical drain cleaning will often solve the problem for many years at a reasonable cost. A camera will show if there is something going on other than just a clay tile drain (such as busted PVC).