I don't know if it's a EU/US thing, but if I google DeoxIT I get tons of WD-40 results in front. Is it the same product? It's certainly cheaper.
Also, I know it's not the manliest of sights, but I use one of these artificial feather dusters for all my gear and so far I've had no dust-related problems. And it's so light you can dust your VCOs without getting them out of tune!