Simulating a touch on a phone screen without a finger?
A standard touch stylus is designed to work just a human finger on a captive screen.  Bonus is that your simulator doesn't start to smell after a couple days.

You have them with hard polymer tip but there's also cheaper ones with a softer, thin layered polymer layer over foam tip.  I don't know where you are from, but in Asian electronic malls they start at about 50 cents a pop.