Not nearly as effective. The oral bioavailability of oxycodone is much higher than it's intranasal bioavailability. It's about a 30-40% drop from the numbers I've seen.
The rush exists, but it is short-lived and the overall buzz wears off much more quickly. I'm sure others who prefer that route would disagree with me on whether or not it's worth your trouble. I would stick with your current route, IMO.