Here's the original proposition:
[latex]$$$ \forall x, \, x \in \emptyset \Rightarrow S(x) $$$[/latex]
where S(.) is the "is a set" operator.
Now, Doron, if you wish to prove this proposition false, attempts at cute word games do not accomplish this. Instead, you need to establish the negation of the proposition as being true:
[latex]$$$ \neg \forall x, \, x \in \emptyset \Rightarrow S(x) $$$[/latex]
Through the miracle that is Mathematics, we can simplify this into:
[latex]$$$ \exists x, \, x \in \emptyset \and \neg S(x) $$$[/latex]
So, all that is required to prove the initial proposition false is for you to exhibit just one example of an element of the empty set that isn't a set. (And it doesn't count if you just make something up that may be true in Doronetics, but isn't in real Mathematics.)