it is not necessary to hid ident after entering in the xponder code for 'hijacking', which is not either of the codes you mentioned, btw. although they are not secrets, it's probably better to not discuss those codes to the point where they become common knowledge.
didn't have much use for transponders flying helos, always squaked 1200 if I recall for VFR. Never had the need to memorize the code for a hijack.
So you don't need to hit ident huh, why when you pull into airspace around major airports and you get put into a holding pattern do they tell you to climb to yada yada and squak 1233 and hit indent?