Since small particle sizes increase the coefficient of diffusion and hence the rate of diffusion one might be able to speed up the dispersion of oil from a spill if one had a means of reducing the particle size of the oil droplets. This is what happens in ultrasonic cleaning. The mechanism is known as sonication in which the mechanical agitation produced by sound waves is used to disrupt the intermolecular forces holding molecules together. Ultasonic cleaning works better if a surfactant is present which helps to alter surface tension. The contaminant ends up as a colloid.
If one wanted to "get rid" of a lot of oil quickly this might prove an effective way of doing so if the object is to protect beaches and ecosystems from being overwhelmed by a coating of oil The trade-off is that a lot of toxins may end up in the water column. Spreading out the toxins over a large volume of water reduces the harm to any particluar location. There may be organisms which can tolerate a small amount of toxins present but as with other pollutants biomagnification can increase the harm done if toxins enter the food chain.