The Good: Pyrethrins, for the most part, do seem to be relatively safe for most pets, though dosage is still the key. Many on-line sites list pyrethrins as being safe for cats, and as far as we can tell, used judiciously, they are not too much more toxic for cats than they are for dogs.
Yes: Razor bumps will usually go away when you stop shaving. There are a few things you can do to prevent them in the future. Shave in the shower so the heat can soften the hair, and use a shaving gel. Always use a brand new razor, and shave in the direction that your hair grows. Moisturize after shaving.
A: When hair curls around and re-enters the skin (an ingrown hair), this creates a razor bump. To rid yourself of ingrown hairs and the resulting razor bumps -- use an exfoliato to remove dead skin cells or a face scrub to free ingrowns. Also, warming the face thoroughly will make shaving kinder to existing bumps.