I am using amf fungi thats arboscular mycorrhizal fungi you buy in packets because I haven't started making that yet. I have been using that stuff for years for trees but didn't realise until a few years ago it was good for grass and other plants too! There is bokashi going in with that, in the bokashi there is biochar dust and I have been crudely grinding up extra to go in with that using just a slab and heavy branch. Didn't mention that in the post so good guess 😆.
At the moment I am mixing it together and pouring it down as most of the water sources I have are chlorinated but I have a filter on one so I will be able to test with some pressure in due course.