I doubt you can get the same effect with a filter, it's just not the same deal, and the whole idea is to eliminate all of the trikery BS anyways(like photoshop)... just press the shutter, be it IR or cross process or redscale... I think filters are good for B&W imagery and softeners and also as an exposure adjustment (neutral density filters etc...) but anything more than that and they take on a bit too much importance I think... But my interpretation of photographic art is by no means the law, go crazy if you feel it's necessary...

-Alan