It probably does help to some degree, and I know it is not the same, these just make me laugh so any excuse to post them... They are probably staged, but you just know that someone somewhere has actually done this, which is why it is so funny.The grease gets on the pistons, which get pushed back into the seals, so probably not the same as greasing seals and pistons, but it isn't dumping oil on the engine. It did make a difference for me.
I just really think if you are going to take the time and effort to do all that, then you mine as well pull them out completely to clean/lube them properly. It really isn't that much more work/mess, and would provide better results for a longer time.