I use a hard plastic spatula that came with a roll of vinyl or spackle or something. I apply it before cutting, and I make sure to squeegee the bubbles as best I can. Some I pop with a pin and go over again with the squeegee. I’ve been doing it so long now that I’m quick.
If you are stacking transparent acrylic, you should use something like weld-on. If you are wedging it between layers of other stuff or are using non-clear acrylic, you won’t see it, and it looks great.
I use it in projects that require glue. Here I have it keeping the 2-tone acrylic to the wood, and holding the base layers together.