I’ve never had a problem showering with the catheter. However, I carefully clean around the exit point and the first six inches of the exposed tube with a clean plain disposable wipe and warm soapy water before showering etc. I do this twice a day. The soap sometimes stings a bit if I put too much on in which case I clean immediately with just warm water.
When I first got the foley catheter I was worried about using my spa bath (hot tube) because that has chlorinated water to keep it clean. The catheter nurse said it would be no problem and it hasn’t been, it doesn’t even sting at all.
When I shower I clip the drainage bag higher up and out of the direct spray so it doesn’t get quite so wet.
I switch legs every few days for the drainage bag but that is to give the skin on my leg a break.