My opinion on that is yes. My brother had a similar laundry venting and had a service clean it annually. In his area at least (Portland, OR) it was a minimal fee and worth it for the safety.

My own runs through the floor and under a room to outside by the patio. When we bought the house, there were obvious signs of it being clogged. (steamy smell in the utility closet it ran under, and dryer occasionally turning off before clothes were dry). I had the duct (a spliced together assortment made of more than one material) replaced with a straight shot of stainless by the HVAC company who inspected my furnace. It was expensive. Worth the peace of mind.

If the brush shown is attached to a drill or something that will spin it around as you push it up and down in the pipe, the debris will be small particles and fall down and out. Otherwise the brush will push everything up and compact it causing a clog at the top. Dryer vent debri is usually very hard stuck lint that does not release easy.

Shop vacuum with a long hose?

Lint residue may adhere to the interior of the ducting, require something more aggressive than a vacuum or spinning plastic brush to remove.

With a roof vent, get a professional to get it cleaned. Better to be safe than sorry.

We have a longer than normal vent. I always clean the duct from both sides to ensure that I remove as much as possible and prevent any blocks like you guys mentioned. I have one that attaches to the drill and removes quite a bit. When I am cleaning from the outside as the last step, I always have the dryer running on air fluff to make sure that airflow will force any loose lint outside. This has never let me down.

Also, I have heard of people using a leaf blower and taping the end of it around the vent duct and turning the machine on to blow the lint outside for about a minute. Seems like a bit extreme and messy!

HU, This is the exact item we have, still in the box. It's part of the LR glam makeover. Our LR did vent straight out the back but 20 years ago we added on to the house, land-locking the LR. So now it takes a left and a 15 ft (horizontal) run. Before the new dryer was installed my husband pulled out any lint he could reach and used the leaf blower to blow out anything he couldn't reach. He still wanted me to order this tho.

I have a dryer venting into the attic. The aluminum tube runs right up to but not connecting to a roof vent. Once in a while I just disconnect the tubing from the dryer, insert the nozzle of the leaf blower and crank it to it's highest setting. Does a great job of blowing out the tube. There's lint all over the side yard though...Haaaaa!

How can it be ok to vent a dryer into the attic? All the humidity can't be good. I'm sure you have attic vents (hopefully) but why not connect it to the vent that goes outside?

That's the way the houses in our complex are built. There is no outside wall as the laundry is in the pass through to the attached garage. Yes, there are attic vents and the dryer tube goes right up to but not attached to one of them, about a 6 inch gap. The house was built in 1994 and the dryer venting has not been a problem. South Florida.

That's a bad design regardless of how long it has been as such.

Vent the dryer properly.

As I said, there is no adjacent outside wall.

Vent through the roof.