The dryer vent is the chore nobody sees until the dryer starts running long, and then everyone sees it at once. Before anybody argues about it, name who checks what, how often, and who keeps the proof.
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Know the path before you split the work
Air from a dryer travels through four places: the lint screen, the cavity behind the drum, the flexible duct running to the wall, and the outside cap with its flap. Each one collects lint, and each one needs a different kind of attention. Walk the path once with whoever is doing the work so everyone is looking at the same thing.
Split the tasks, not the blame
Three jobs belong to three different people. Emptying the lint screen after each load is a household task, and a helper who is already in the home can do it along with the laundry. Checking the outside flap for a blockage or a nest is a visit task for whoever drives by. Deep cleaning the duct and the cavity is a hired job, and it belongs to the person who books and pays for it.
Write down who does which job. A one-page list taped near the laundry room works better than a text thread that scrolls out of sight.
Set the schedule, then keep the record
Agree on how often the deep clean happens. How much your mother runs the dryer matters more than the calendar, so ask the person doing the work what they find inside the duct and adjust from there.
Keep a written log of each cleaning: who did it, what they found, and what they fixed. The log is the most useful thing in the folder when a new helper starts, when a sibling asks whether the job got done, or when the dryer starts taking more cycles than it should.
What to ask the person who cleans it
Ask whether they clean from both ends, the dryer and the outside cap, and whether they check the full length of the duct. Ask whether they will write down what they found. Ask what they would look for if the dryer began running hot or taking longer than usual, and which of those signs means calling someone else.