The answer to 'dryer vent greasy' is that a greasy dryer vent is typically caused by a buildup of lint, dust, and fabric softener residue. This can create a fire hazard and reduce the efficiency of your dryer. Common symptoms include longer drying times, a hot dryer exterior, and a musty odor.
The best solution is to clean the dryer vent regularly, at least once a year. This involves disconnecting the vent from the dryer, using a vent brush or vacuum hose attachment to remove the buildup, and then reattaching the vent. If the vent is heavily soiled or difficult to access, it's best to call a professional vent cleaning service to ensure it's done properly.