Yes, but practicing "badly" will just reinforce bad habits. The key to getting clean barre chords is this: whenever you get a poor sounding chord, STOP. DO NOT CONTINUE PLAYING. Then, micro-adjust your finger(s) until the strings ring cleanly. Usually, all it takes is a slight rotation or a small lateral shift of the barring finger. When it finally sounds clean, concentrate on your fretting hand and try to remember exactly how it feels at that point. Then, take your fingers completely off the fretboard and see if you can duplicate the chord cleanly once more. Eventually, your muscle memory will take over and you'll no longer have to think about it. The only way to get there, though, is to slow down, get your hand to do the right thing, and repeat. It is very important to STOP playing and correct the problem immediately - not just "power through" the rest of the song hoping that it will get better through practice.
