The organic spray is MUCH more effective than the normal kind, especially on a roof.
If you spray with Raid or similar, the yellowjackets will chase you a bit before they die. This is bad if you are on a ladder. With the organic stuff, they just fall down dead instantly.
Plus it's made out of mint oil, so it smells good in your AC :).
It also might work to spray some preventatively at the beginning of the summer, to encourage them to build there nests elsewhere. Yellowjackets are good in the garden (they eat aphids), just not near where people hang out.
'Poison Free' is the brand, sold at big box stores.
Source: I work in an area with a LOT of yellowjackets. At least, it used to ;).