I make a hand call that does a vocal (vocals make them less sneaky and many times trigger vocal response), and I have lots of tutorial material (look at the call-in story page on my website for starters.) But if you're serious about giving it a go, you're far, far better off getting a programmable remote electronic call. You can definitely call them in with a hand call, but an e-call is just way better in many ways.
You don't need a super high end one, (FX3, Scorpion, M1, etc.) just make sure it's remote operated, and it's programmable. For a new one I recommend the firestorm on a budget, and the CS24krakatoa as an investment. (I don't represent any caller company, btw.)