I have just done a bunch of Husky filters, both nylon types and the Flocked type. I just fill a bucket up with warm/hot soapy water (strong washing machine concentrate poweder) and let soak. A nice soft clean paint brush for any scrubbing after they have soaked and usually it is bugger all as the soaking has loosened every thing up so much. Rinse very well with clean hot water.
If you filter is 2 piece, definitly crack it open and do both parts. As has been stated by Rick, the manufactures and a filter engineer friend of ours, do not use more than 10psi of compressed air on any filter. Above that you pretty much are damaging the filter material. Just becuase you cant see it doesnt mean its not happening.
My filters in my STihl blower and string trimmer both say to NOT WASH, just replace with new. These are a bit different to the chainsaw filters I have experince with