The O'Jay's "For The Love Of Money" the great Anthony Jackson, when he was 16 or so (or very young if not exactly 16) used a flanger and at the beginning some reverb.
Bootsy Collins uses envelope filter tones all over Parliament/Funkadelic.
"Funkify Your Life" George Porter, Jr., uses an envelope filter, recorded by The Meters. He also uses one briefly at the beginning of Robert Palmer's "Sneakin' Sally Through The Alley".
Larry Graham with Sly and the Family Stone uses fuzz on "Dance To The Music", it's double tracked though, he adds the fuzz bass track on top of the clean bass. He uses fuzz on a number of other tunes that I can't recall off the top of my head, too.