Depends on the active ingredient, which isn't listed. 1% coriander oil, 94% canola oil, and 5% Triethanolamine. I don't know about that.. the oil is mostly useless even if it annoys the insects, lol. Not suae about the triethanolamine... wiki doesn't even list pesticide as an application.
An 'all natural' option are pyrethrinees... those kill on contact. Like this product, i'd buy a concentrate that you mix for yourself. the pre-diluted spray bottles are not as cost-effective.
The key here is not marketing terms like 'natural'... they key is how fast it breaks down and whether or not any residual is safe to burn and inhale etc... 'organic' or 'natural' doesn't necessarily correlate to any of that. Each molecule used needs to be assessed on an individual case. if an 'inorganic' compound breaks down to nothing concerning in a matter of days, it's the best option regarldess of the peanut gallery's feelings on the advertising terms organic vs inorganic, lol.
I wouldn't recommend spraying anything on the flowers... but at least this stuff has a short half-life. There's nothing that will be effective and safe to spray on something you'll smoke later.. that's just not realistic. 'food safe' doesn't mean it's safe for something you later burn and inhale, either -- or extract with solvent or vape.
if you do use a foliar spray, cover the flower as best you can as you do it... google 'half-life' of the active ingredient.. can't assume things.. e.g. pyrethrines have a half life of 48 hours, if i recall.. so every 2 days half of it remains... which after 2 weeks is 0.7% ... seems small but may still be dangerous. That concern will vary by molecule, too.. some may need to get to .00000001% to be safe and others may just need to get below 1% etc etc... depends on the molecule in question not whether or not it is "organic' or "natural."
Cyanide is "natural" ... CO2 is inorganic, yet the carbon the plant gets from it is the backbone for nearly every molecule it builds. There's a tone of false perceptions and extrapolations from the advertising terms "organic" and "natural".