Strongly recommend biting the bullet and replacing it entirely with proper rigid duct. If that entire run is flex-duct, it never should have been installed in the first place. Really bad news. Basically you've been lucky for 18 years. Don't push it.

Don't clean it, replace it with rigid ducting which is safer and much easier to keep clean. (In fact if this is the first time you're cleaning the coiled stuff and you're replacing your old dryer because it doesn't have the same old oompf, the problem could actually just be a clogged stack, not the dryer itself.)

Either way, replace the coiled stuff with a rigid duct for both convenience and fire safety.

The materials for replacing an existing duct are pretty inexpensive and the requird skill level is low. This is a good DIY project.

Molly~

I need to retract this post! I just watched the video we made of the mechanicals in the house before we closed up the basement ceiling, and the duct is the rigid kind. So I guess we can go ahead with any type of cleaning we want!

Thanks for the commments and advice. I've found a chimney sweep to do this initial cleaning and then perhaps I can manage it on my own. I've purchased a product at Menards which has a dryer duct cleaning 4" diameter brush that attaches to a 20" flexible rod so I can snake it to one end and pull it pull it back out again to loosen everything up. Only $14.99. Then I guess I'll use the leaf blower to send it all outside.

Good on ya. Doing what you said will have you in great shape although the chimney sweep is likely overkill. Glad to learn you've got decent ductwork in there!

And you're very smart to have made the video.

Good luck!

Molly~