Help with bottlebrush and Oleander removal?

I'm going to be revegetating my in-law's hillside in Palos Verdes this winter to coastal sage scrub. Right now I'm clearing the area of weeds and a number of non-native shrubs, including Oleander and bottlebrush. What are the most effective ways of killing these shrub species? When I cut them to the ground, they sprout back up in no time. Is herbicide the way to go, or will I have issues with chemicals once I begin planting the natives?

Thanks!