(check it)0. onActivate>Self>setEmitter>Testicals
(no check)1. onActivate>Self>setEmitter>NONE
(check it)2. onActivate>Self>toggleEventEnabled>Type "0 1"
Makes it so when you click it, it switches the checks between enabling Testicals or enabling NONE. I'm sure there's an easier way to do this, with only 2 events, but I've forgotten and this works just the same.
I'd be happy to make a small tutorial on some basic event stuff, but only basic stuff because that's as much as I can do. Most events, as I see it, aren't ALWAYS straight forward, press this, it does this kind of stuff. You sometimes have to plan it out, or trick it into working in some obscure way. You'll get the hang of it though.