Hello fellow commuters!

I have been commuting rain or shine without fenders for a while now but I'm looking to get some for the rainy season. I run a late 80s Bianchi with about .25 inch (or 6ish mm) clearance from brakes to tire ( 700 x 23). I would prefer something that can STAY on and not taken off (I have tried some and they just aren't as stable as I'd like). Does anyone know if a) this is possible w/ this clearance and b) what fenders COULD work. I've been to some bike shops but they weren't very helpful. Thank you all!