Hey there,
For what you described, you could use both functions or SSEs. The main benefit of SSEs in this case would be that you could target multiple devices at once, rather than having to call each one separately. If your main goal is to trigger just one device, I’d go for the function call.
There aren’t really recipes on IFTTT as far as I’ve seen, but it’s easy enough to make your own 
Here is some example core for your device that will set D7 (the tiny LED) HIGH for 5 seconds:
#define ledPin D7
bool toggle = false;
void setup() {
pinMode(ledPin, OUTPUT);
Spark.function("ledPin", ledToggle);
}
void loop() {
if (toggle == true){
digitalWrite(ledPin, HIGH);
delay(5000);
digitalWrite(ledPin, LOW);
toggle = false;
}
}
int ledToggle(String command){
toggle = true;
}
On IFTTT create a new recipe. The “If [this]” is up to you. For the “then [that]”, select Particle, and “call a function”. Then, from the list of devices, select the one to which you flashed the code above.
That should be it. Once your IF trigger gets triggered, you should be able to see your LED light up 
Sorry for the late response, this one must have slipped through somehow. I’ll delete the post in the other category to keep things in one place.