No, you cannot 'unvistit' an area. You might be able to simulate going there as if you had the quest, however. You would need to CLUAConsole:SetGlobal("Variable","GLOBALS",X) it to get by.
Icen
You do realise this is for vanilla BG1, right. So therefore, with the profiency groupings of BG1, Short Swords is the correct one.
Daggers as a proficency doesn't exist in Vanilla BG1.
Icen