In my limited experience (with larger diameter pipelines), the drip is more of a preventative measure than a cure.
Meaning, if you have a solid block of ice at a sag in your line, the alcohol will not immediately melt the block and open the line. The alcohol works normally by depressing the freezing point of water.
Keep fiddling with your system, hopefully it will come around and you can avoid a bigger repair. No guarantees, but at least I am crossing my fingers for you!
