I suspect the "filtered" refers to reducing RF interference that would show up as noise in TV's, DVR, ect. these filters are made up of small capacitors and inductors.
There are some things you can due to round off the output for example filters made from much larger capacitors and inductors but the higher the current output the higher the cost, higher internal heat and a bulkier unit and you still have a MSW just "slightly" cleaner.
You should be able to use a MSW inverter with most refrigerators but not all depends on the manufacture.
