Sounds like a plan and good luck with it. Urinary incontinence can be self perpetuating in that you tense up because you think you'll have a problem peeing and then you do. It has not been unknown, for those on temporary grounding, to have 2mg Diazapam prescribed 3x daily to aid relaxation or Amitriptyline at low dosage on a short term basis. This is though, most definitely a personal matter to be discussed with a medical adviser and would almost certainly have CAA consequences. That leaves hot relaxing baths while you drink beer and float plastic battleships on the water's surface which you can try to torpedo from underneath with the urinary blast as the beer on the inside and the warmth on the outside make their effects evident.
Don't let your girl friend know you're doing this. Women have strange problems with shooting in bath tubs.