This home had an accordion style vent attached.  Once we cleaned the dryer vent, we explained the importance of changing the dryer vent to either a semirigid or a Dryer Flex, and the homeowner opted to do the upgrade himself so we provided him with information about what to purchase at the local hardware store and walked him through the steps and tricks to install it, which is to pull the washing machine out and install it from that direction.  This is because semirigid vents, unlike the DryerFlex we use, does not have a lot of expansion capabilities and you do not want to create unnecessary bends, twists, or loops in the run.