A mild solution of bleach works on really tough mildew odors, but is best reserved for towels, wash cloths, dish cloths, maybe some bed linens, that sort of thing. There are commercially made bleach sprays (Clorox and others) that are very convenient and sometimes work better than homemade preparations. In particular I like the Clorox foaming bleach spray for kitchens and bathrooms because it's easier to confine the spray to a specific place. Works on kitchen and bathroom brushes, sponges, etc., too. So far I haven't seen any bleach damage from using these on kitchen and bathroom cleaning cloths, but I'd use it only as a last resort on a backpack, satchel, etc., or clothing.
Grout lines in the bathtub/shower stall are notorious for growing mold if not kept in check. I have found that keeping a spray bottle of Clorox foaming bleach or a spray bottle of CLR (or Lime-Away) in the bath area reduces clean up time. Once a week after a shower, simply spritz the cleaning product on the grout lines. Finish getting yourself ready, then before leaving the bathroom, rinse down the stall with warm water. Lime-Away also works wonders on the glass of the shower stall. Do this regularly and you will never spend a precious Saturday morning scrubbing your bathroom.By from Tennessee