Basically, the filter is Jim Sterling while he's on all four like a horse with his mouth strapped to the customer's anus while he's chewing Orbit Gum. It's currently being tested in Jim's Lab (Holmes' House) in Boston. When the customer farts, Jim inhales the fart and convert the smell into a aroma that anyone can enjoy by breathing it out with a minty breath, while keeping the trumpeting fart sound we all love.
For example, when Holmes is at the Mental Hospial Idiot Ball eating Devilled Eggs, he can do a tingle with a little bell that's sitting on a table and the Sterling Corp. Fart Filter will come crawling from beneath the table to attatch itself to his anus. Thus when Holmes' boss J. Jonah Jameson is yelling at Holmes, there's no risk that he might make him further upset by filling the Ball Room with a bad stench. During the process Jim will also be yelling and everyone will be surprised that it smells like Orbit Gum and JJJ will buy one for a thousand dollars.