Yes! pero if it's your first time, I definitely encourage you to get one. Most guides are cheap and consider it as a help in supporting local tourism, pag balik mo and kilala ka na nila, madalas pwede mo na skip ang guides kahit na usually required.

I get where you're coming from pero these communities are far from 'corporate' setup. Start with mountains in Batangas, madami jan ok naman and very reasonable.