Making your own 'twister ruler' is very simple and if you use a non-slip square, sliding is not a problem. Cutting on a slightly lower table than usual so you can put more body weight on the seam intersection makes a big difference as well. Here are two tutorials for making the ruler.
http://firstlightdesigns.com/?p=1120
http://www.quiltingboard.com/main-f1...ls-t57130.html