Cleaning of Polarizing Filters with Lenspen

[knockyPole]

Hi Guys,

I bought a lenspen,FilterKlear to clean the finger prints on the lens and filters etc. Then I realize behind the package of the lenspen it said do not use it on the polarizing filters.

I guess it's because it will wipe off those polarizing effects right? please correct me if i'm wrong.

Do anyone just use it on the polarizing filters but gently? Or how do you clean the smudges without the lenspen?

Thanks in advance!