The last time I had a bladder infection I used cranberry juice.
There have been times when I had frequency and burning and it seemed to have been due to toxins I had eaten in food. I did a search for 'burning urine toxins' and there are other causes than infection. If you wash throughly and then catch the middle part of the urine stream in a clear bottle, usually with an infection it will look cloudy. If your wrine is always cloudy this test isn't much good.