It happens to everyone sooner or later. I recently got a taste sliding down a logging road for a good 20 feet, luckily mostly on my back, but I probably would have healed better if I'd sucked it up and scrubbed out the gravel. Saw this article...
Cycling Weekly: How to treat road rash
As soon as possible after the crash
, after checking yourself & others for more serious injuries, stop any bleeding, and temporarily cover the wound until it can be properly cleaned and dressed.
Unfortunately, the best way to prevent infection and speed healing is rather unpleasant. You should scrub the wound to get out all the small rocks and dirt, and then scrub with iodine, betadine or normal saline. The post ride shower is a good place to do this painful task.
The rash should then be covered for at least 24 hours. Pros use dressings containing alginate and silver, which absorbs the oozing wound juice and forms an anti-bacterial gel. Iodine gauze is also recommended. Tubular gauze will keep dressings in place.
Curad Hold Tite Tubular Stretch Bandage
Make sure you're taking in a good amount of protein during your recovery, your body needs it to repair tissue.
Remember that covered wounds heal faster
and leave less scarring, the idea that exposing a wound or scab to air to dry it out and heal faster is a myth and exposes the area to potential infection from airborne bacteria. Keep it covered for at least 24 hours.