Sometimes balloons will work better if you're going to use anything more than an SM57 or an SM58 (which are usually ideal since you'll only be losing about $100us if something were to go wrong and the mic gets damaged.
Rule #1, ALWAYS use unlubricated condoms. Lamb Skin condoms smell really funky so completely avoid them, even the unlubed ones; besides... skin is more delicate and prone to tearing easier than latex.
Also look into the balloons that are typically used for bending into animal shapes, as they're pretty durable and shaped well for things like shotgun mics. You also might want to get a pair of soft tipped reverse jewelers pliers to help get the opening open large enough to get it on your mic. Typically these "animal shape balloons" will be more "form fitting", have a tighter seal and not leave a weird smell that might make your clients think weird things about you if they ever get close enough to your mics to smell them.
As far as for cleaning them I would suggest very carefully using unscented baby wipes, as they typically have very gentle chemicals if any at all. They're actually really great for cleaning a lot of things (as I found out very quickly after my wife and I having our daughter 4 years ago).