Denny I use the same approach as you did in stating my intent to new employees if they are caught stealing from me.
If you state it prior to them working for you and before getting to know them, they don't take it "personal" like they have a flaw.
It works well for pre-nup agreements also,if you want one bring it up as a conversation PRIOR to getting serious while your getting to know each other and then they don't take offence later when you ask for one..you can just remind them of the conversation you had one night early in the relationship .. eek