I just tried putting my camera on a tripod, then shooting an object, moving the object a bit, shooting again, move some more, etc.
Image stacking median just about made the object disappear while leaving the background visible.
Christoph's 100/1, 100/2, etc. and image stacking mean produced what looked like identical results, in which a ghostly version of the object appeared multiple times (once for each capture) against a constant background.
Each image was on a separate layer. To do image stacking, highlight all layers, then Layer->Smart Objects->Convert to Smart Object. For mean or median, Layer->Smart Objects->Stack Mode->[Mean or Median]