best way to clean a multicoated Polarizer filter

I have a Hoya Multicoated polarizer filter and some how it got a "smudge" on it and it has been a bugger to clean any suggestions? I have used lens cleaner and micro cloth from 2filter.com but with limited success .

Have a look at the bottom of this Hoya page for their cleaning recommendations.

http://www.hoyafilter.​com/products/hoya/coat​ings.html

thanks _ I ask at a camera store and they could not answer at all - I will try this

Have you tried to initially clean using a fluid, but then simply huff the dry filter with your breath and wipe with microfiber to get rid of the residual streaking?

I use Residual Oil Remover (ROR) on an annual basis, along with microfiber, and I do not have issues with streaking when cleaning my Hoya filters.