Food-grade H[SUB]2[/SUB]O[SUB]2[/SUB] leaves no residue but plant-roots won't tolerate peroxides in large quantity . . .
It would need to be highly diluted but the plant's metabolism would speed up resulting in increased vigour!
Sodium chlorate kills plants by releasing oxygen at such a high rate that roots are over-stimulated, leading to plant death!
I just might try very dilute H[SUB]2[/SUB]O[SUB]2[/SUB], myself, one of these days . . .