I've never smoked a joint with a roach or tobacco in it. I just don't see the point. I only smoke joints rarely though. Around here you just smoke the joint until just the roach is left ("roach" here means just the end of the joint with all the resinated weed in it) and save it for smoking later. If you can get a whole bunch of roaches, take off all the papers and pack all the resinated weed into a bong, and you will get royally toasted.