In the youtube clip with the 909 and the Juno, what the guy doesn't tell you is that he's using the rim shot trigger out on the 909, not the audio. This is designed explicitly for triggering other instruments. The DrumBrute only has audio outs. You can't use these as triggers because a) the level is too low, and b) it's an AC audio signal rather than a DC voltage trigger. If you did amplify it to a suitable level to use as a trigger each hit would actually produce multiple triggers as the audio signal bounces around. You might get it to work but it's probably going to be flaky.
You can use the metronome output as a trigger, but you can't program a pattern into it. The easiest way to do what you want would be buy something like a beat step which has trigger outs, or a midi to cv converter, or a second hand TR606 which has trigger outs from its tom tracks.