People also have to realize that no matter what you say they are going to do it anyways. So instead of trying to talk them out of it provide useful info on the subject so they can make educated risks. Its like telling your kid to wait until marriage for sex to prevent them from getting STD's. Instead of telling them what STDs are you just tell them no sleep overs and go to church. Since you wasted your time preaching abstinence your kid could get aids unknowingly then spread it around because you assumed that its a perfect world where abstinence only is realistic.
That is actually quite good example. And because many people (especially kids) do extremely stupid things knowing nothing about risk and protection they jump into something carelessly (copying older as monkeys) and rely on some troll's "infos" on internet ("articles", forum, wikipedia etc), instead to get information from right sources.
Go to the restaurant, for instance, and order something to drink. For 1 Euro and 5 minute break you may get Hepatitis C and STD some other as well. On opposite example, go to the dentist to get rid of caries and you may easily get similar. Buy food at some place you always visit and you may get food poisoning and die as well. Go to hospital to make simple operation and you can be dead from hospital-acquired infections. Etc... These are not examples, but real events and real people.
Piloting, gliding, driving, riding motor/bike, cross the road etc... All the same, the risk is always present.
The main point is, that there is many things that is not under your control and instead, must to trust some idiot on word that he done his job correctly, trust always by default and hope to the best, or learn their job as well to recognize symptoms can affect on your life as well. What you can control yourself, you doing it the best you can (learning in well controlled environment ) or not doing it at all. If want something to learn, learn it from right sources - do not rely on "infos" from internet made by unknown credibility person(s).
In short, you can risk by many ways jumping into uncontrolled and controlled situations - you, your son/daughter, ... can get hurt badly or die. Then what is the point ? The whole life, every second is risk assessment, decision and action. Otherwise, you may sit in your house safe and sound and wait to die by natural cause, earthquake, could rob you, kill you or a plane could hit your house...
Honestly, your approach keeping out information that you studding chemistry and asking at first such banal questions with false conclusions, then revealing yourself as an expert in chemistry and self answering is not proper way at all.
Always keep in mind that many actual beginners read this! And many of them are not capable yet to "digest" or distinguish what is really important and what not in handling HCl. For them it is the best approach the safest way (ordering finished PCBs or at least using Ferric Chloride).
Maximum safety is a fallacy. If you are going for maximum safety you are not going to make your own circuit boards. You aren't even going to make your own circuits as you could get shocked, burnt, or start a fire. You won't get anywhere in life if you don't take some risks.
Maximum safety, well educated about the matter and maximum attention is the key when handle hazardous materials, especially for hobbyists. Let review briefly my own "fails" experience in electronic as a hobbyist:
When started, I have blow up some fuses, LEDs, burned some resistors, ICs, short it, etc... - all in controlled experiments and low voltage circuits.
Accidents: I had I or II degree burnt from iron when started SMD soldering under magnified glass (nothing serious, just briefly tip of iron touch), slip few drops on Cupric Chloride on concrete when moved etched PCB to container with baking soda, few times inhale fumes from soldering, did inhale some HCl when prepare Cupric Chloride bath...
Nothing serious really, but these "accidents" happens when I was over competent considering that all is completely under my control or had less attention - these mistakes may easily get quite worst... I'm still doing PCBs, repair my own devices... However, did not touch old CRT TV (even it is rich of parts may be quite useful), as I do not have tools to handle high voltage from cathode, power supplies, and similar...
All according my current knowledge and practice as a hobbyist in electronic, I do not reach over my limits. In my profession however, I push myself out of limit all the time - that is called progress, doing as well other hobbies... Otherwise I would do some boring physical job whole my life all over again and nothing else.
No doubt others will try the experiment like he did and wont be so lucky.
Exactly the point here. Many beginners in etching reading this will now say: "Nah, some people here says to be extreme caution but other says HCl is a peace of sh... What a bunch of morons! I could do some pranks with my self, my brother/sister..."
Well done! As well, there is many videos on Youtube move PCB right out of etchant (without neutralization) under tap water and right to the sink, actually they dump down the drain right away whole etchant without neutralization...
You have also wrote:
Ferric Chloride seems to be the best chemical except for its not safe to dump down the drain but I can manage safe disposal.
Then:
I like HCl because there's no toxic waste. But are there some methods this won't work with?
"Ferric Chloride seems to be the best chemical except for its not safe to dump down the drain but I can manage safe disposal" Then: "HCl produce no toxic waste" ?!
And then you claim you studying chemistry and self answering claiming that you love to shock people?
All that is absolutely irresponsible from you - there is no pranks with extremely hazardous materials, especially with other people may get all that as granted.If that is true, you must be in early 20's and do not know strict laws regulative about handling hazardous material. BTW, I could be your father by age.