Influence of books on general mnemonics

Harry Lorayne et al.'s The Memory Book and Dominic O’Brien's How to Pass Exams gave me a lot of thought on revising or recreating some mnemonics in my published book, Learning Spanish Words Through Etymology and Mnemonics. For example, this word

pizarra slate, shale; blackboard (in a classroom), scoreboard (for sports).

requires a convoluted description to barely relate it to only part of the English word dilapidate (literally “to destroy with stones”), a connection hardly helpful to the learners. Instead, I would probably rewrite the entry to say something simple, like "Imagine the board at the front wall of a classroom is a big pizza". I bet those memory books' authors would say the same, maybe even more dramatically, changing "big" to "gigantic"... After all, the goal is to remember the word, while etymology is just something nice to have if or when it helps.