the directions on the bottle are probably not for labor induction. the cohoshes are used for menopause, and i imagine that's probably more likely what those doses are in reference to.
did you get a homeopathic or a tincture? the dose will be very different depending on that. sounds like a tincture to me since it's in drop form. and according to Susun Weed's Wise Woman's Herbal she says for Caulophyllum "3-8 drops in a glass of warm water or tea, repeat every half-hour for several hours until contractions are regular. if labor is not underway in four hours, use a dropperful of the tincture under the tongue every hour for up to four more hours or until contractions are strong and consistent." for the homeopathic Caulophyllum, the dose is to be repeated every half-hour for two hours (those are usually small pills that you dissolve in your mouth, which doesn't sound like what you have). But then she goes on to say that one midwife uses the tincture hourly and the homeopathic every half-hour, which establishes a smooth labor within five hours, and that she does not discontinue until labor is established. For cimifuga she says 10 drops under the tongue hourly. she doesn't say for how long, though she does say it should have a noticeable effect on the cervix in three or four hours.
I get the impression she advises the cimifuga first to ripen the cervix, and then the caulophyllum to encourage contractions. though she does recommend them in unison for stalled labor, but not for initiating labor.
it is worth noting that the caulophyllum can elevate baby's heart tones, and can also lower your blood pressure.
if i were you, though, i'd ask your midwife how she recommends you take it since she's the one who advised you to take it in the first place. i think everyone probably has a slightly different regimen.
i'm curious to know if it works. if i'm still pregnant this weekend, i might just be trying it. though i'm going to go with the homeopathic versions, as i understand they are more gentle for both mama and baby. not to mention a lot easier to take than tincture.