What will rustchek do to a K&N air filter? The reason I ask this is I'm going to get it done.I know I should cover the Airaid filter during spraying,but what will the after drops do to my K&N?

------------------
4.2 auto 4x4 F150
Blue With Silver Long Box
Airaid
235/85/16 Goodyear Workhorse Extra grips
Duraliner Bed liner
Cl#3-4 Acar Reciver
Ford oval Hitch Plug