I hate to waste food too, but I wouldn't eat something if I thought it might make me sick. Besides, my nose isn't that sensitive, and by the time food smells bad enough to bother me a bit, it's probably pretty rank. Sometimes I've left beans soaking longer than I intended to, but never longer than 24 hours.
Beans can be sprouted, and they take a few days- but I think they're normally kept just wet with plenty of air around them.
Every snowflake in an avalanche pleads, "Not guilty". Stanislaw J. Lec