If you fudge extending the F412 string you can do an ex invis and then follow up with either a slide or claw pounce. Once you are on top of your opponent, mix up low pokes, grabs, B32, B3 - DB2, F41, F412, B2 + some combo, and NJP attacks relentlessly. I'm finding that experienced players tend to block low while newer players tend to block high. The problem with B2 is that I lose track of where I'm at and miss since you have to be right on top and players will poke aimlessly hoping to hit you.
Jumping into players can work too but I've found some people throw an uppercut when they see the dust indicating that I just jumped.
Otherwise, I don't use invis that much. It really requires the enhanced version and EX slow ball more or less achieves the same purpose of letting you open up on an opponent, but invis is more effective against people who know how to read and block the F412 string.