Is not simple as it seems.
The only way I found is to use a function in the revert
option and than use jQuery delay
to wait your time, dealy was build up for other purposes (queue and animation) but in this case is working fine.
Code:
$("#draggable").draggable({
revert: function () {
$(this).delay(5000);
return true
},
revertDuration: 1000
});