Annie, I am not sure. It is the last bit of advice my DM ever gave me.
We had moved house a few months earlier and the lawn was infested with a tiny round leaved thug that had killed off most of the grass. I had tried lawn weed killer and salt, but without effect.
I never actually tried the Jeyes Fluid as sodium chlorate was still legal and having accidentally got some on the edge of the grass when spraying the front path and seeing it kill this pernicious plant, I said 'What the hell', sodium chlorated the whole lawn, dug it up and started again.
20 years later it is beginning to come back but - alas - sodium chlorate is banned and unobtainable.
I would think you diluted the Jeyes Fluid.