My current experience (CIS and just finished week #3 of Induction phase).
They use a numbing jelly prior to catheter insertion. I wouldn't say it's painless, I would say uncomfortable. Removal of catheter - painless, quick, less uncomfortable than when it goes in.
Holding BCG, I stop all eating/drinking 2.5-3 hours prior to procedure, I relieve myself as I walk into the office, and the catheter removes all urine, prior to BCG injection. Once home from the quick procedure, the process of laying down and rolling a 1/4 turn each 15 minutes continues for 2 hours. I have found that laying on the stomach makes the urge to urinate worse, so I do do left side, right side, back, then stomach,,, to push that position to last.
And don't forget, after procedure, after 2 hours of playing rotisserie and turning every 15 minutes for 2 hours, then you expel the BCG and need to place bleach in the toilet with expelled urine for 20 minutes, for the next 6 hours.