It has been mentioned before, yes. Not a cure for CFD, especially since the CFD nanites are capable of reproducing with whatever the subject eats, without a nanohive. In someone already infected, it would slow the spread, essentially like giving chemo to someone with terminal cancer.
Where it has real potential is in people who are newly infected, or aren't infected. Nanoplasmosis could be used to innoculate people, essentially similar to giving people immune system boosters. So, no cure, but possible prevention.