I shave my current longhaired girl, although she is hard of hearing if not completely deaf. I do have extremely quiet clippers for doing dogs faces, trimming with scissors can take upwards of half an hour depending on how co operative she's feeling which can be stressful, with the clippers is takes 5 minutes tops and doesnt bother her at all.
For most of my other longhairs that ive had scissors worked well, I kept the hair under the main bulk and around the back legs nice and short, I dont let it grow much more than a couple of cm, the main skirt of hair gets cut floor length. Although they were usually straight haired, my current one is curly so it's a bit all or nothing
but I tend to keep the whole back end short and the sides long so she's more hygienic. I only ever bath when absolutely necessary, it's really easy to rub knots into the coat during baths and drying, so I usually wipe them down with an unscented wet wipe as and when needed, the ones I like best are waterwpies, they're a bit more expensive but they're pretty much 100% water with a little fruit extract, but any unscented, aloe and baking soda free baby wipe is fine. Bum baths are also an option where you just dip their bottoms into water, instead of wetting the whole pig, this is far less stressful way to bath.