HYDRAULIC!
I swear, I think I'll f#%king puke if I see another person misspell this word (or any other common word) while engaging (or trying to engage) in a technical discussion.
I know ZIP about firehose nozzles, with one exception. They don't go from being 100% closed to 100% open as quickly as a nitrous/fuel solenoid does. I imagine part of this is because it takes even the strongest human longer to ramp that nozzle valve to 100% open than it does for an electric solenoid to ramp its valve to 100% open. For all intents and purposes, when comparing the solenoid to the fire hose nozzle, the solenoid is being opened to 100% instantaneously.
Is the solenoid getting "hammered" when "stuttering" it with a progressive timer? Depends on what you mean by the term "hammered". You see, the solenoid will see the same conditions (ie - pressure spikes on the inlet side) when closed over a longer period as it does when it is "stuttered" with the timer. It's just seeing more of them, over shorter periods of time when being "stuttered" with the timer, and like any mechanical device, this will result in an accelerated wear rate.
'Dude already covered it pretty well concerning atomization and the "tuneup" with his most recent posts, so there's no need to beat the horse any further in that respect.