well, if you have a sense of rhythm then surely you can make one to four bars of a drum pattern onbeat without a metronome. in fact, a lot of times people get throw off by them because they start anticipating metronome strikes instead of just following the natural rhythm.
like puff said, a metronome is just a timing device. use it to tick on anything you want - be it end of bar, cuts, digs, whatever. when it comes down to it if you're using a mpc then it technically shouldn't let you introduce samples offbeat, so i odn't really see your insistance in wanting to use a metronome. just tap out eigth notes and you'll be fine.