Inserting a catheter in your uretra - and I'm not even talking of removing it - is actually one of the most painful experience I've ever had... if I were supposed to be tested for a test/epitest ratio, I'd rather find a way to increase my epitest level...
That being said, you better take a shitload of antibiotics if u ever decide to fill your bladder with someone else's urine... odds to get an infection in the process are quite high...
No doubt... it's very painful! You've got to remember that the nurse that's inserting the cath most likely doesn't truly give a shit whether it hurts or not, so they aren't going to use enough lube and probably aren't going to use the smallest catheter available because they aren't wanting to have to have issues with it.
And urine is sterile, unless the person has a bladder or kidney infection.
As I said...if the difference between making $4 million and being out in the real world is just a 5 minutes of pain, then I'm going with the pain.
If they give you enough time, then there are much better options than this. It would be a last resort.