I've advocate by doing. I work at a computer repair shop with honest rates, and transparent practices. I volunteer at repair cafés sharpening tools for free. This way you demonstrate directly towards them what you're doing and what companies are doing.
I can show customers that apple's ribbon cables are thinner than tissue paper, all of the freaking glue holding it together, the serialized components, the convoluted design, etc.
Whenever I speak about it outside of the repair shop people think I'm some conspiracy nut, but people will listen with the evidence right in front of them.