OK, I used to knock these out all day long. I've done every method known... then on a whim, I busted out one of my "Big Squeegees" and decided to just "push it on" from the top down. HAHA!! I just laughed it was so easy, and got mad all at the same time for not having tried that before.
So the key here is that your "Blade" that you are going to push with is as wide as the window and perf. You can just have it a wee bit narrower if that's all you got, but really should be wider. But sometimes those commercial windows with the aluminum frame kinda dictates the size of everything. I ended up making about 10 different ones to fit various jobs I kept getting. So I pretty much have one for nearly every window size up to the widest width of my vinyl.
You only gotta peel back about 3-4 inches at the top. Stick it on with a felt squeegee... and let it hang there and you can see if it's going to be lined up. The most important thing here is to keep the carrier paper on and as you are pulling down it's pushing the paper off as you go. It does help to have someone pull the paper off as you go, but they can't get ahead of you or you'll end up with creases or the perf stretching. As it's prone to do. It's pretty fast and easy, and you don't have to get their windows all wet again after you've just cleaned them.
But if you really are in a jamb, and need to go "wet" I highly suggest using Invisible Glass in the spray bottle. Not the one with silicone in it, the original. It works really well and evaporates on it's own without leaving any reside in the perf holes. It's more expensive than a spray bottle of denatured alcohol / water mix. But at least it's consistent formula that works.