Not to be picky, but I think you mean a mnemonic (mnemonic (n-mnk)adj. Relating to, assisting, or intended to assist the memory. n. A device, such as a formula or rhyme, used as an aid in remembering).
An acronym is a word formed from the initial letters of a name, such as WAC for Women's Army Corps, or by combining initial letters or parts of a series of words, such as radar for radio detecting and ranging.
While an acronym can be a very effective mnemonic, I think there are too many letters in the scout law to form a good acronym.
If you come up with a good mnemonics, I'd love to hear it, I've been trying to think of one for some time now. I keep drawing a blank. Good Luck.