Scirocco Register

Fitted a K&N filter some time ago and seem to remember it being touted as a "lifetime" jobby. I assume they do need a bit of maintenance though, like a good clean to get all the crap out?

Do they come with some magical potion to clean them, or am I imagining things?

There is a cleaning solution and oil available to buy. Halfords sell it and i guess most car parts shops would.