The first one 10 peopleminimumto do, due to how the mechanic works. When other achievements that required 10 people minimum existed, they were removed from the meta. (The let the boss steal your entire raid group’s clothes one in Mogushun is one that comes to mind) The second one ...
CAUTION: We've received reports that players are having trouble getting the gong to work. Note two things: 1) Hit the gong ONCE and only once, then wait. Hitting it more than once can cause it to glitch. 2) Remember: you must be in a raid group with at least one other player....