Soak for twenty minutes in warm Epsom salt water. Scrape the loosened scab off with your nice blue thumbnail and lift out the pus kernel. It should be attached to the scab. If you see any more pus, waxy stuff, scrape it out.
Clean very well with soap and water or Betadine. Then squirt with Vetericyn, let dry, then goop on some antibiotic ointment and bandage well so no dirt gets in. You can let her go back to her dirty life and check the wound again in two days.
If it is a shallow case, you may be able to leave the bandage off, but you may need to soak again and re-bandage.