I’ve always developed my own medium format Ilford HP5 with little to no issues.
Honestly, getting film on those plastic spools can be tricky regardless of the film. There are a few tricks people suggest that might help (e.g. lubricating the ball bearings with pencil graphite, and using an old scrap of film as a lead-in to get you started) but loading them is something you just have to get better at over time.
I’m with you - celery is horrid. Right up there with coriander for me as something that completely overpowers and ruins anything it’s used in.