How do you clean a paint brush with oil based paint on it?

at our paint store there is a small tool with a semi circle on one side and a sharp set of spikes on the other, you get the majority of the paint off with the spikes and after that a paper towl, then put the brush in a large ziplock bag that's airtight and the brush will stay soft. if you want to clean the brush to use with other paints, the orange handsoap powder that you get at a hardware store will suck the oil right off, but make sure to really rinse the soap off before you use the brush again.