[Ben Harmless]

Couple of ideas:

-Yes, absolutely clean that '58. Remove the ball and dip it in mouthwash, and then rinse it out well.

-Alternately, just remove the ball entirely. The grill was designed to protect the mic capsule. It's not entirely beneficial to the sound of the mic.

-It might also be worth trying a '57. I personally like the '57 on my voice, and use it live whenever I can.

-The Shure Beta series tends to have a little more high end response and articulation. The Beta 58 is a decent mic, and the Beta 57a is a good vocal mic as well - Sting and a bunch of other guys use 'em. The Betas also have tighter patterns than the SM series, which will help with bleed.

-If you're not liking the vocal tracks, try using a bit of subtractive EQ. If you've got a parametric or semi-parametric EQ on the vocal channel, try rolling it down and then sweeping the frequency knob to see if it cleans up a bit. I'd play in the 300-800hz area, and start by cutting about 3db - actually you can start with a much bigger cut to try and locate useful frequencies, but don't overdo the final setting to the point of it sounding weird.

-Also, if there's a high-pass filter on that channel, engage it. There's nothing in a live vocal mic that will do any good in the mix. The same goes for all the other mics in the room that aren't on things like bass or kick drums (maybe toms too). This can really help clean up a vocal track.

-Lastly, a little compression can help a vocal stand out in a mix. It can be tricky though, so unless it's obviously helping, forget it.