IMHO you should take it to a vet and have it cleaned out properly. The pus needs to be removed, the wound flushed and the dragon put on antibiotics after doing a culture and sensitivity test to see what bacteria is involved. Af you don't its quite likely that it will go systemic and your dragon will die.

Reptile pus is thick like cottage cheese and can't be penetrated by the antibiotics/white blood cells so the infection is not likely to clear up if the pus isn't removed.
Good luck!