There are many different types of enema nozzles available – if you feel like changing the standard nozzle that comes with your kit.
This is the type of nozzle I want to purchase next. I haven’t personally tried this nozzle but I did have an “incident” with the stock standard nozzle that was a little uncomfortable. I believe that the tapered head on the along with the fact that the holes are not directly on the outside, would prevent any feelings of it catching on the skin on the way out. This one also comes in a set so you get the clamp and a smaller nozzle with it.
If you are ok with the standard nozzles, then its probably a good idea to replace them regularly so you are always using one that is nice and smooth. The Kinmann store sells sets of 12 so you’ll have no excuses.