Cranberry juice is one effective treatment, but it has to be pure cranberry juice, not the cocktail kind in the stores. You'd want to drink 16-24 oz per day.
Uva ursi, helps to kill bacteria. It possesses a compound called arbutin, which the body converts into a bacteria-killing substance. In Europe, uva ursi is widely used to treat UTIs. If you drink too much cranberry, it can affect the PH of your urine. In order for arbutin to work, you need to have alkaline urine. This can be accomplished by taking a small amount of baking soda.
Goldenseal and Oregon grape both contain berberine and other alkaloids that kill bacteria and stimulate the immune system. These herbs also appear to inhibit infection-causing bacteria from adhering to the wall of the bladder, so they are sloughed off in urine. These should not be used for more than one week
Herbs that have diuretic abilities can help wash away bacteria. Dandelion leaves are diuretics.
Marshmallow root is great for soothing inflamed areas and it enhances immune function to help fight off unwanted bacteria.
Juniper berry is also sometimes used.