See the link below. You can skip some of the video if you wish but at about minute 12 the applications of wood vinegar in agriculture are discussed. The ratios given for pesticide and weed killer seem to be reversed so you would want to be cautious about using it.
I doubt that wood vinegar could be used as a pesticide in aquaponics without harming fish but I'm not sure. What do you think? Maybe a small amount sprayed directly onto the pests would be ok? Anybody have expertise in this area?
As to producing it, I believe it would be rather simple to do, especially in small quantities.