It won't work as was found out in Libya. Qaddafi retained a hidden cache of chemical weapons and the US will be wary of any such proposal. In reality the Syrians are never going to allow the in depth and intrusive inspection regime that the US would require before it signed off on any deal. The Syrians could simply retain an undeclared cache or covert production while handing over a token of their inventory.
Inspectors uncover Qaddafi?s hidden WMD stockpile | Homeland Security News Wire
OPCW Inspectors Verify Newly Declared Chemical Weapons Materials in Libya
Syria still won't allow the IAEA full and unrestricted access to the Dair Alzour site struck by Israel in 2007. You can imagine how they would react to any deal that would involve intrusive inspections in regards to chemical weapons?
http://www.iaea.org/Publications/Doc...gov2012-42.pdf