Last cycle I had heard about Robitussin to help with CM. WHAT? Guaifenesin, the active ingredient in plain Tussin acts as a mucus thinner. The primary component of Cervical MUCUS is mucus (semen too).
Everything I've read suggests taking 200mg 3 times a day. So I go to my local pharmacy (Walmart) and pick up an 8oz bottle of Tussin for $2.50. It should last me near two cycles. Take it for the 5 days prior and including the anticipated date of the big O and you'll notice a difference.
Things to keep in mind when trying this. Use the plain formula or you may find you get the opposite result. Antihistimine medication can actually dry up CM, and some other active ingredients may cause birth defects. Also be sure to drink extra fluids during this time. Caplets might also help since liquid cough medicine tastes pretty nasty.
I'll update my findings!