Drona the pot born. Ok here is the interesting story of not just Bharadvaj' son Drona but Vyasa's son suka as well as Rishi Chyavana's son Pramati.
Rishi Cyavana's son Pramati marries apsara Ghritachi and has a son from her named Ruru. This story is narrated in Adi Parva. Section Puloma Parva
Now the same Ghritachi while bathing in a river is observed by Bharadwaj and he masturbates. And then collects the semen in a pot and out comes from the pot Drona. Who is named so because he is born from the pot.
The very same ghritachi is observed in the form of a parrot (playing with parrots/or dressed in a green parrot color dress) while Vyasa is preparing for a yagya.
Vyasa sees her, she sees vyasa but she scared of the rishi takes a form of parrot and flies away Vyasa sees her and masturbates and his semen falls on arani sticks kept for the yagya and from it pops out Suka. Named so because Ghritaci looked like a parrot when Vysa did the job..
So now make of these stories what you will.
There is another mention of Ghritachi with another puru king raudrashwa and she gave him 10 sons aparently..but it must be some other ghritachi as it happens atleast 3 generations prior.