duke, sorry i didnt mean for it to bash you or the special ed kids. I really did do it in 3rd grade. I think everyone did haha. I think it works well with celery because that's mostly water and tissue.
With marijuana, i think it just sits in the soil and the roots wont take it up.
BUT, im not sure about during the veg state. Maybe it works better, and you can see results when it starts flowering. Id only do it during veg then stop once flower, maybe it will do something, even change the color of the leaves. hmm?