I really disagree with this suggestion.
I have to caution against leaving soap in that area....ever.

Soap is highly alkaline and our skin requires a modest acid environment to kill bacteria. Leaving soap anywhere on the body invites irritation and worse.

Best to use a gently moist compress of first aid hydrogen peroxide to cleanse that area.

Eating probiotics or Kefir will provide beneficial organisms to keep that area free of pathogens. This is a much more useful approach than leaving soap. The antibacterial soaps will also kill off beneficial bacteria and make matters actually worse over time.

In the area and on the area are 2 different things. A drop of soap is what I am recommending not left on [not in] for days but can be for a for a day or so. Preferably hours.It is not a health issue that requires a change in diet. It also is not a matter of cleanliness.

i have intersistal cystitis same symptoms

Try a bit of baking soda in the bath water. If natural remedies do not work, see that doctor again. You could even be allergic to some medication, so keep track of when this itching is at its worst. Itching means something is out of balance. ginnie

I realize this is an old thread, but that these issues are common, especially for those that have neurogenic bladders or are immunosuppresssed.

Diflucan is an option if a fungal infection is stubborn.

Rinsing quickly with Hibiclens after activities like swimming in a pool or other bacterial exposures helps keep down UTIs.

Ask for Macrobid prophylactically if you frequently get UTIs following certain activities or other predictable factors.

Negative urine tests and low urine cultures don't mean anything. According to research, only 30% of women have positive urine tests with UTIs. If it improves with treatment, it's probably a UTI. (It's not necessarily interstial cystitis.)

Be careful with cranberry if you tend to have allergies. I ended up developing an allergic skin reaction after a year of drinking cramp berry juice daily.

Some different things to consider:
Vitanica Yeast suppositories...they are all natural anti yeast suppositories. I believe they have a tiny amount of boric acid in them. But only use if you feel you have a yeast infection. Don't hesitate to take RX medication if this doesn't work, but this might do the trick.

D mannose....read up on this. I take this if I have even the slightest suspicion I am getting a UTI or if I have relations. I also take it if I have an odd pains "down there" or itching. Many people take this daily. It is a product that many people buy from the health food store. You can read up on it at www.iherb.com. If you purchase, just try to get a name brand and follow the instructions. If you can cut back on the amount of antibiotics you take, it very likely will help you with the itching and overall. I've heard of people taking this daily and their UTIs stop. Something to investigate and consider!

Avoid sugar, flour and soda BIG TIME! Hard to do, but a necessity! Greatly limit alcohol.

Consider taking a good probiotic.

If you are post menopausal, consider speaking with a doctor who uses bioidentical hormones to see if you are a candidate.

Drink lots of good quality water. I'm finding that the better my quality water, the better I feel.

Wishing you well.

Grape seed extract contains anti fungal, anti viral and anti bacterial properties. I'm headed to 2 decades on it and no UTI's in moons.....knocking wood.... I agree with Vowel Lady too on avoiding nasties.... I take a 30billion probiotic daily, digestive enzymes and the love of my life, grape seed ex..... CLEAN WATER all day.