Inventing cute mnemonics is fun, and the process of inventing and checking them may help reinforce the definitions, but beyond that they really are useless – and I believe they do more harm than good when people actually try to use them.
It takes much more time (and mental effort) to correctly recall and decode one of these than anyone who needs to use the terms can afford. And there is a much better way.
Just think ‘Sine is the Side’ or ‘Cos goes Across’ (we don’t need both)
This takes negligible time to decode, reinforces the concept directly, and is immune to the vagaries of failing memory. (Was that “Odd Aged Teachers Are Happy Campers On Hot Sundays” or “All Old Teachers, Happily Out Camping, Have Amnesia Sometimes “?)