How can I clean my white vinyl dryer vents? Normal tools seem to tear them. How can I prevent fires?

We live in a 20-yr old condo community, so replacing the vinyl with aluminum is a daunting proposition. But I'm afraid they've never been cleaned and could lead to fires. The HOA will never pay for the replacement. And even if we replace them ourselves the other residents in our complex may not, which could still lead to fires in our condo. HELP!!