Ask 10 people and you'll get 10 different answers. Just how it is with many things.
I'm new to ARs and have been researching a lot. Used to grab the foregrip same as you mentioned. Heard about, and tried, the "thumb break method". While it does take a little (and I mean little) getting used to.....I find it's awesome for me. Practicing more and more to make it a habit. Muscle memory and all that.
It's explained a little bit here:
http://mytumultuousadventure.blogspo...ak-method.html