The Loiseau is the technique to get open the guard by digging the elbows into the inner thighs. I call it the Loiseau after David Loiseau, the UFC middleweight known for his brutal elbow attack.
Kid Peligro teaches a counter to this. Peligro has the guy open the guard up just enough to re-close the guard around the guy's upper arms. This prevents him from posting with an arm, easily allowing himself to be swept.
I've had a hard time with this counter. Peligro admits that it has to be done quickly, and I suspect that long legs don't hurt the effort, either.
Here's the counter I'm thinking of: the perfect attack would be the triangle choke. By digging his elbows into your thighs, the top guy is exposing his neck and wrists. This gives two of the necessary handles for the triangle choke.
The first task is to get an underhook. I think you can do this by opening up your guard and stepping on the hip while pulling on the wrist of the same side. This should help isolate the one arm by stretching the guy out. It also makes it easier to attack the neck on the other side because you can use the step on the other side to help lift your hips up.
Push off with the step foot, swinging your other leg around the neck and pulling the arm toward you. You want to get as perpendicular as possible to make the triangle choke efficient.
You can also get a sweep from this motion if the guy's base is not good, or you get an exceptional pivot off of your step foot.
Whatever you do, don't let go of the arm on the step side. He may try to shuck your neck attack leg overhead. Keeping that arm will make it more difficult to pass if he does. It will also make it easier to reset your guard.
