To be sure you get all maggots out of tissue, I used Catron IV screw worm aerosol successfully. They just fell out of the wound. I gently washed away the area, like you seem to have done well, with a shower head. There's a puff powder used for pinkeye called NFZ Puffer (nitrofurazone). Use a little triple antibiotic just enough to lightly coat the area. You can use a conservative amount of NFZ on the wound once it scabs over and starts to heal to keep it from infection. The tough part is preventing picking and reopening of the wound. A light spray of Bitter Apple chew repellent for dogs may help, or Vet's Best hot spot spray. I never used any antibiotics for this situation. I just made sure I supplemented water with nutrients. I'm glad you saw it before it was too late. Warm weather sure is a dangerous time if vents get dirty and flies are abundant to lay eggs on them. I trim around vents of some of the more feathered breeds to help keep things clean. A pair of scissors or electric clippers work well.