Rinsing your mouth regularly promotes good mouth health in general. However, risking lipoid pneumonia from swishing an oil in your mouth for 10-20 minutes sounds like added risk with no additional benefit over standard rinsing or brushing methods.
Dr. Steven Novella has a great article discussing the present data on oil pulling.
“There is no reason, either theoretically or based upon any evidence, to recommend oil pulling instead of standard modern health care with flossing, tooth-brushing, and mouth rinse. However, it does appear to be better than nothing, and might have a role in developing countries without access to modern oral care. The one caveat is that extended periods of swishing that are commonly recommended (10-20 minutes) are likely not necessary and further present a risk of lipoid pneumonia from accidentally breathing in small amounts of oil.”
Skeptoid’s Brian Dunning also has a great breakdown of this issue with some great references that you can find here.