DIY is appropriate for some vents, not every vent.
Use this screening guide before reserving. Never access a steep roof, unsafe attic or confined space to complete a rental cleaning.
Good DIY candidates
The dryer can be safely unplugged and moved; the transition connection is accessible; the exterior termination is reachable from the ground; the vent route is reasonably understood; and there are no signs of scorching, melting, gas odor, standing water or separated ductwork.
Stop and request help
Stop if a rod disconnects or a brush becomes stuck; the duct appears crushed, punctured or separated; there is scorching or melting; you smell gas; the line contains water; airflow stays weak; the dryer continues overheating; or access requires a roof, unsafe attic or difficult crawlspace.
Drill-direction rule
Threaded rod systems must rotate only in the direction specified for that kit—generally clockwise—so the connections remain tightened. Use low speed and controlled movement. Never reverse the drill while rods are inside the vent. Follow the instructions supplied with the actual rental kit.