Sounds like your buddy is just using the organic title for marketing purposes. That is unfortunate, but not uncommon.

Here’s a source that doesn’t fit your buddy’s description…

Along the central coast of California, conventional strawberry growers apply chemicals like methyl bromide, an internationally banned substance that is no longer being manufactured, but is stockpiled for exemptions to the ban, which these growers exploit. Alternatively they have been experimenting with methyl iodide and other hardcore synthetic chemicals. They hire undocumented laborers to apply them.

Organic strawberry growers, on the other hand, use crop rotation of a brassica crop as a bio-fumigant, and they grow rows of alfalfa as a trap crop where pest infestations can be literally vacuumed up with a tractor implement.

In this case, there is a huge difference.

It is true that the National Organic Program is a joke, since they let the board get taken over by corporate big ag long ago. That doesn’t mean “it just makes people feel good and there is virtually zero difference”. In some cases it does, but to paint the whole thing as such is denying the larger reality.

The general difference with organic pesticides and herbicides is they tend to be less persistent in the environment (lower half life, less off-target impact, etc). Organic farming was never supposed to be about human health, it was supposed to be about environmental health. The program was also suppose dto use chemicals as a last resort, instead relying on different agricultural techniques from the typical mass monoculture farm. Instead it has been mostly hijacked by people just doing the paperwork and switching which chemicals they're spraying.

Like what specifically? It is certainly true that there's little difference between naturally and synthetically sourced chemicals of the same identity (ideally, where supply chain doesn't affect composition)

But at least naively, these all seem like the least concern: Fairly well behaved nutrient stuff like phosphate rock, nitrates, sulfur, etc.; while all the concerning compounds are synthetic or semisynthetic (besides arsenic lead etc. which have been out of use for a long time right?!)

AFAIK there is no natural source for most of the concerning pesticides/herbicides like glyphosate, chlormequat, paraquat, aminopyralid, maybe synthetic/semisynthetic pyrethrenoids etc. while the much smaller list of "natural" pestidides (pyrethrum, any others?) aren't concerning because they degrade quickly etc.

But I'm also assuming here that "approved for organic use" means "the substance can be trivially extracted from natural sources" which might not be true

It depends. I suspect large organic brands are more likely to be like that.

But locally I've visited some of the small farms we buy produce from, and they use very minimal sprays, or none at all and instead plant companion plants that attract the pests to them instead of the main crop.