This my understanding of it...
Both are good for plants... both can do the same job. Usually organic nutrients require a bit more added to the water than synthetically derived fertilizers because synthetically derived fertilizers are typically salt based and are more concentrated. Both are made from things you personally wouldnβt go out and consume on your own and are things you wouldnβt really want to smoke either.
Think of it this way, producers/farmers everywhere use chemicals in their crops each and every day. Most of the crops we consume do not go through any kind of βflushingβ period like we do marijuana and most are grown with synthetic fertilizers. There is a small niche market for organic products but the vast majority are not organically grown.
In the marijuana industry, it seems most home growers grow with organic nutrients only wether from their own opinions or simple superstition.
Plants convert the nutrients they uptake in the soil into the energy and sugars they need to survive. It does not remain the same. The chemicals you put in the soil/water should be different altogether in the plant since the plant breaks these chemicals down in their metabolic processes. This is why we can feed tomatoes mature water and the tomatoes still do not taste or smell like manure.
Just like in vegetable farming, any kind of sprays should not be applied to the end crop. In this case our end crop is the bud and to prevent chemical buildup on the outside you should mitigate how much ends up on the outside of the plant once flowering begins.
Feeding directly into soil-the plant should have little if any of the chemical fertilizers you use. If using organic, again, it will have little if any.
Foliar feeding-as long as it is done before flower you should have very little residual amount left.
I am currently experimenting with plants to see if flushing has any real effect on the end bud. Iβm not convinced that flushing is truly needed as no other crops are βflushedβ before consumed/smoked.