With your privet, cut it off on a warm day (afternoon) when the sap
is flowing and IMMEDIATELY paint the stump with strain
roundup,,,,wait a few seconds and the stump will suck it up,
repeat,,,,,,wait a bit longer, repeat.......wait a bit longer........


Some of them will still come back, but I've yet to see them survive a
second round. I've done hundreds of privet like this and that is
what worked.

That would still require committment! And I don't use roundup. The one I
beat was because it was next to my front door so every time I left the
house I could scrub off any new growth. The ones I haven't beat are in
my back yard...