The big squeegee is a great tool, but like all tools it's not a cure all.
If you have bad technique with a regular squeegee, then you will have
bad technique with the big squeegee, thus causing bubbles and wrinkles.
I would find it hard to describe technique here... maybe someone else would be better at it here. Or maybe someone can point to a video.
Briefly, a good squeegee with no nicks in it. Hold the squeegee on a 45 deg angle with much pressure. I try to imagine an arrow, and pass the squeegee over the center of the arrow as I move down the panel.
Once you learn it, you won't need fluids.
Like Flame says.... Practice.... Practice..... Practice
jt