Inoculants for biochar charging

Just curious, what is your inoculant?

Combo of urine, whole wheat flour, ag lime, seaweed, compost, rotten fruit, rotten wood, and worm castings.

Whatever you put into biochar as an inoculant will be trapped inside and gradually released over time.
If you use something with a high nitrogen content, it will naturally release nitrogen (bound nitrogen, of course).
Therefore, I highly recommend using a complex fertilizer, such as manure of any kind.