There less than a handful of studies on 25b exempt study to prove residual.
The majority of 25b products on the market are not manufactured by chemists but by marketers.
There are no real efficacy studies in the field with multiple pest species almost all studies are performed in vitro.
Only one product on the market EcoRaider has documented testing.
Efficacy of an Essential Oil-Based Pesticide for Controlling Bed Bug (Cimex lectularius) Infestations in Apartment Buildings
Potential of Essential Oil-Based Pesticides and Detergents for Bed Bug Control
Long-Term Efficacy of Various Natural or “Green” Insecticides against Bed Bugs: A Double-Blind Study
Posttreatment Feeding Affects Mortality of Bed Bugs (Hemiptera: Cimicidae) Exposed to Insecticides
Evaluating the Effect of Minimal Risk Natural Products for Control of the Tick, Ixodes scapularis
The fact that most manufacturers have little to no pest control experience, with no real testing in the real world and with specific pest and products have been targeted to over the counter consumers which have no experience in pest control creating a demand for professional products with no training and no experience.