According to James Fallows of the Atlantic, in the case of Yin Chiao pills, yes and yes. But that article was prompted by all the people writing in to warn him of the dangers of herbal medicine and/or lack of efficacy. Still, just as many readers reported success, and survival, after taking Yin Chiao. (h/t Yunnan Herbal)
I’ve taken a lot of TCM cold and cough remedies in my time in China, but actually never heard of Yin Chiao. The one I’m most familiar with is 京都念慈菴川貝枇杷膏 Nin Jiom Pei Pa Koa. I initially took it for a perpetual sore throat, though it seems to be marketed as much as a cough medicine as sore throat reliever. Is it safe? I’m still here, so I guess no harm, no foul. However, it’s super sweet and in that way can raise your blood sugar and become quite addictive. (They also have a much harder to find no sugar formula.) Does it work? Well I took it for a sore throat and I did have relief overall, but it also has slight numbing properties which are immediately effective. Pei Pa Koa is mixed with hot water and drank like tea. If it at least gets you to drink more hot water, essential for flushing germs out of the body and actually getting healthy again, then it has worked. Would I take it again? Yes, probably.