I don't know the exact phrase that means a Pokémon is at max...uhhm, unhappiness. But to actually obtain a Frustration TM, I grabbed an old Poochyena that was in the Box since I caught it, went to the Pokémon Herb Shop in Lavaridge Town, & bought 3 Revival Herbs (2800 each). I then had the Poochyena faint, then used the herbs to bring it back, only to repeat the process until I ran out. It was enough for the man who gives Return/Frustration TMs to give me one for Frustration.
It's MUCH easier to utilize Return than Frustration, & much less expensive. Frustration sounds more fitting to vicious Pokémon like Gyarados or Mightyena, but Return is going to serve you just as well.