I politely disagree. There are some basic standards that all piercers should follow. Autoclave use is the first and most important. Internally threaded jewelry is one, metal quality is another, minimal use of clamps is another as well, and any qualified piercer should also know about proper saline soaks and how to mix them. There are also some very basic safety thresholds of medical knowledge in piercers that you can look for as a client as well- for example if a piercer tells you to put neosporin/antibiotic ointments on a piercing, that would be a piercer to definitely think twice about as they literally aren't reading the instructions on the tube that say not to use it on puncture wounds. It's common medical knowledge that piercers should be expected to adhere to.
I agree that there is variety in preferences from piercer to piercer even at the forefront of the body mod industry, but in terms of best standards and practices for piercers in general there are some bases of knowledge that clients can and should use when evaluating who to choose because they are basic thresholds for the industry. If you read journals and periodicals out there written by and for industry artists, those standards are commonly discussed. I wholeheartedly agree with the "ask your piercer advice," but only where the piercer is competent. And I just try to provide some advice on what those minimum standards are so that people know what questions to ask to determine whether a piercer is competent and whether the service they received was safely provided. In sum, yes there is variety, but not on an infinite scale. I don't personally tell people to just ask their piercer if I don't know anything about the piercer. Maybe he doesn't even have an autoclave, doesn't even wear sterile gloves or keep a sterile field for piercing. If I don't know that, I won't just say ask the piercer, I try to talk about what the basic industry thresholds for a clean, safe piercer are. If they meet those standards, then the person can know they are totally safe in following that person's medical advice.
No offense intended. I speak from a place of over a decade of involvement in and study of the body mod industry as a whole and I try to vigorously defend the position of those who fight for the base standards of the industry. There are a lot of people piercing who dangerously do not follow the most basic of common medical and industry knowledge because there is basically no standard regulation or licensing for body mod artists- the community still has to define those for itself right now. Sorry, this touches on a passion for me.