Can I revive these two hedges

two years ago I used gallop 365 to kill brambles within two different hedges. One is privet the other I’m not sure, it is variegated and an olive type leaf.(I’m not much of a gardener that could be inaccurate) I used it with a very strong mix and it worked but has killed parts of surrounding hedges. It didn’t rain for months after I applied it and damage got worse killing grass about a foot from the hedges.
I hoped it would come back but might have got worse. Someone told me to water with Jeys feud a couple of times but no change and iv left the hose on Soaking it try help it. I dug between plants and put manure chicken feed pellets down last year but no joy. This year I have watered with gromore but no joy.
I thought the privet was dead but on cutting it is not I tried snapping a bit but it bends doesn’t snap and appears to be alive but without leaves. Both hedge (different plants ) have some very very small leave adjacent to the damage area.
I don’t know if it will come back or I should dig it up and see if new plants will grow.
Any advice appreciated