The wording in question is as following under the Directions for Use for Liquid Pyrethroids: "Other than applications to building foundations, all outdoor applications to impervious surfaces such as sidewalks, driveways, patios, porches and structural surfaces (windows, doors, eaves) are limited to spot and crack and crevice applications only". A specific exception to this is "treatment to soil or vegetation around structures". So, this raises the question - is gravel closer to "soil" or to "sidewalk", and my opinion (and only my opinion) is that gravel would not be considered an "impervious" surface. If you treat gravel or crushed rock with a spray application it would be unlikely for rain or irrigation to flow off of that gravel and carry the pyrethroid with it, as it would if the spray had been applied to wood decks or concrete surfaces. You spray should soak down through the gravel and into the soil below. 

But, please do make that phone call to your local regulators and get their opinion on this too. The whole intent of these new restrictions on the use of pyrethroids outdoors in non-agricultural settings is to reduce runoff that would carry the active ingredients into local waterways. It has been determined that even tiny levels of these active ingredients could affect aquatic organisms, and since we really don't need to have the active ingredients in what we spray flowing off the property the new wording is intended to add assurances that what we apply stays where we apply it. There is no reason to spray the top of a concrete driveway, nor to apply granules that end up on the sidewalk. This is a waste of good insecticide and leads to the greatest chance of having that material move off site. Treatments to soil and lawns are likely to stay put as long as the soil is not already saturated to the point it cannot absorb any more liquid, nor to frozen soils that also will not allow the spray to soak in.