I take a sachet of Urizone every month (urinary antiseptic, not antibiotic) to prevent UTI's and a glass of citrosoda every night, to alkalise the urine. I had bladder cancer 10 years ago, and had surgery and 6 months of chemo, so I am very prone to UTI's, plus I have urinary retention because of the ms...I have not had a UTI since I started this regime. Frequent UTI's for me could lead to a recurrence of the cancer, so I am especially careful.
As an ex-midwife, kegal excersises are very effective for strengthening pelvic floor muscles - weakness here caused by pregnancy can lead to incontinence, particularly stress incontinence.
However, I am not sure if they are effective for strengthening pelvic floor muscles that are weak due to nerve damage (ms) - but it can't hurt to try! You have to be consistent and persistent - every day, twice a day, for a few months before you see a difference, but after 2 babies, huge episiotomies and forceps deliveries, I can personally testify to their effectiveness.
Also, there are medications, and devices that can be used to control incontinence that is caused by a neurogenic bladder - chat to a Urologist, again, it can't hurt to try, and it might make your life much more comfortable.
Take care & I hopethings improve for you.