Just a home owner.If you want to do it on your own equipment go ahead, but if you are in business NEVER on a customers unit, unless you have great liability insurance.
Most pushers use a paper filter.What kind of filter are we talking about here? Paper or foam? If foam, are you oiling it. A dry foam filter will let dirt by.
I have two push mowers. One has a paper filter, one has foam. The new small Briggs engines without chokes... have foam filters.Most pushers use a paper filter.