I've used all of these methods to clean out a vacuum hose at one time or another:
1 - Connect the hose to the "output" end of the vacuum cleaner and blow the blockage out. 2 - Drop a weight down the hose and shake it so the weight pounds the blockage and dislodges it. 3 - Put a garden hose in the vacuum hose and use water pressure to dislodge the blockage.Yes, the last one is a bit extreme, and you should let the hose dry out before you use it, but trust me, it works.