[Only Ornamental]

I wouldn't use DNP cause it's fairly toxic for humans. Amongst others, it has been used as a weight loss drug back in the day. It's cheap and pretty efficient... unfortunately, it also has a small margin of safety and got a few people killed. Since then, its use as a drug is prohibited but it remains one of the favoured drugs used to spike 'herbal and natural' weight loss pills one can buy on the internet. It's said to be metabolised quickly by plants but an educated guess ain't good enough in this case.
On the other hand, DA-6 seems one of the few PGRs I would be inclined to use cause of its neat biodegradation and relative absence of toxicity for humans. Did you try it? Seed soak, soil drench, or foliar? Which concentration?