The best way to get any dirt out of the wound is to use copious amounts ot water. H2O2 ( hydrogen peroxide) was used in the days where other antiseptics like chlorhexidine were not developed yet. I still remeber my old surgery tutor professing the uses of H2O2 on abscess cavities.
Now, we shy away from such chemicals as the peroxide tends to affect the new tissues growing up from the base of the wound.
Still useful as a hair bleach though......