Incase you're having trouble with the web rodeo trick/attack, here's the 411. You first web tie the enemy, (up to 4 enemies to be exact, it doesn't matter how many enemies you web tie) then you spin the left analog stick as fast as you can. (clockwise or counter-clockwise, your choice. If the first direction of spin doesn't work, try the other one.) This attack is good when you're surrounded. It temporarily clears your position, but after that brief moment when your enemies are knocked away, they could get back on their feet and easily attack you again, if you're not carefull.

P.S. try to web rodeo your enemies off buildings because sometimes that's an instant kill. Also, try to web rodeo your enemies into the water. Now that is a 100% instant kill.