I am memorizing Barron's word list which contains around 3500 words. My experience is it is not realistically possible to use mnemonics when volume of memorization is as much as 3500 terms which you have to do in as short as three months.
I used a book "Remembering the Kanji" by James Heisig, which employs a special mnemonic technique, to learn to write 2000 Japanese kanji in three months, which was a leisurely pace (twenty-something a day). Many people did the same in a much shorter time, like 100 a day. It works beautifully. If you have problems learning those words, you are most probably either using the wrong technique, or using it incorrectly.
And it works! I have been using this method since 2009 and am quite comfortable with Kanji. When I started, I did 20 characters per day and was done in a little over 3 months. Though the real acquisition was in the years that follow.
