Some info: http://forum.playredfox.com/index.php?threads/assemble-and-disassemble-system.200/#post-3277
Basically you disassemble decos and weapon for materials to be used in costume gallery and some crafting. The higher the refine lvl or number of slots and ornies in the deco the more materials you get.
The disassemble bag is where materials from the(disassemble) process are stored; Refined weapons and garments (clothing & decos) can be undone, or disassembled----taken apart for materials----and the tool to disassemble is purchased from General Merchant, or Item Mall. The material (Red Stone) you gain from the process are needed / used for crating other weapons and garments etc...