I had to self-catheterise (is that a verb??? Dunno) for about six months after an optical urethrotomy to deal with a stricture. For the first couple of weeks I was doing it daily, then twice per week for the remainder of the six months.
Really it is no big deal. I started off with a size 12 (quite small) then 14 then, for the majority of the time size 16 (one down from hosepipe). The catheters are disposable so you don't have to worry about cleaning after use. The procedure is simple - hold penis somewhere near vertical so there is a smoothish curve of the urethra down, then up again into the bladder. Gently insert catheter until it stops (usually hitting the sphincter and/or opening up a stricture), apply gentle pressure until the sphincter lets it through then stop as urine appears in the tube.
The size of catheter you can manage obviously depends on your anatomy. You may assume what you like from my ability to use a size 16.... The worst part was having to demonstrate that I could manage the insertion of the catheter in the presence of a (female) nurse..... After six years of living with prostate cancer and its after-effects, you would think that I would be used to revealling all and having various orifices probed and examined, but hey ho.
Incidentally, no sign of a return of the stricture.