B&S always works for me, and I use Decursive. In fact, Decursive is designed with B&S in mind to show when I have a poison effect on myself.
If, OP, you're talking about what DBM tells you to keep moving on (which it says in really REALLY big letters, by the way), then dude...just KEEP MOVING. How is that hard to grasp?
If you're talking about rogues, then man, they refresh poisons on each weapon attack. Good luck getting that junk off most of the time.
If you're talking a hunter, then same thing applies. Unless it's Wyvern Sting. Then you can just trinket and then remove the poison afterwards. Works perfectly fine.
I don't know what issues you're having with B&S, but it sounds more like an operator error. The talent works in it's entirety for everyone else. If it's just you, then it's not broken. You are the issue, not Body and Soul.