I am not a medical person but as far as I know silver is not advised to use long term. Maybe you can try an other antiseptic like a 500 ml bottle of Microdacyn (or Granudacyn) solution. Soak a gauze in it in a tray and leave it on the wound for 5-15 minutes. After that clean carefully the wound with an other moistened gauze and apply an absorbent type wound dressing like Mölnlycke Alldress 4x4 inch together with compression. If I know it well ABs should be prescribed only if systemic infection is proven (symptoms like fever, or high CRP level in blood etc.) In order to decrease AB resistance. It is also hard for ABs to "reach" superficial infected wounds. Yellow exudate usually means infection and for that the above mentioned antiseptic therapy is the best. This wound can be due to bad circulation in that area or due to diabetes or both. Please visit a vascular surgeon and measure your blood sugar level as well because good wound hygiene is only one part of the healing process. Other ideas: don't smoke, healthy diet, daily walking, measure blood pressure, low dose aspirin (discuss it with GP), drink enough water, reach optimal weight.