You can even make the furniture invisible and lay it over something else, so it serves as an invisible animation layer.
To make an object in Second Life transparent, right-click the item you want to modify and select “Edit”. Now it should be highlighted in blue and/or yellow.
While having the object selected, go to the Texture tab. Set the transparency to 100%.
To see all transparent objects around you, hit Control-Alt-T. This will make them all light up in red. The same command will make them all invisible again.
