I would say a lot of people on the interwebs seem to think HCl and peroxide == cupric chloride. I spent a bit of my own time convincing probably the smartest (in electronics knowledge) guy I know that cupric chloride is not just weak, used up HCl + peroxide.
To etch metal, you need two things. Acid is the first. But acid will only etch oxidized metal. So the other thing is an oxidizer.
So in HCl and peroxide, you are using the peroxide as an oxidizer. It is indeed a very strong oxidizer... but it is unstable and spontaneously dissociates into water and oxygen as soon as you mix this up. So it is very good etchant for someone who etches very infrequently and doesn't want to build an etch tank. But it can't be stored. HCl and peroxide is also not as accurate of an etchant. It has more undercutting than other etchants.
Ferric chloride oxidizes the metal, but this oxidizing agent gets used up in the process. Unlike peroxide, this stuff is stable on the shelf forever. But once it's used up, it slows to a crawl. Adding some HCl will help it continue to work. This creates CuCl2 from the used up ferric etchant. And essentially you will start to have to use this like Cupric, by using air regeneration. And eventually this initial batch of ferric will turn into curpric chloride etchant (with some extra iron contamination in it).
Cupric chloride is popular because the oxidizing agent regenerates itself when exposed to the oxygen in the air. To use it effectively, it requires aeration.
The way I do it is with a vertical etch tank, bubble wand across the bottom, and I hook this to an air compressor with a regulator. It takes only something like a few psi, probably under 10 for sure. A little fish tank thing will work, but it is quite a bit faster when you get it almost frothy with bubbles.
The only thing you need to do is add some more acid and water now and then. I'd say you use up (very roughly) about 1/2 of a turkey baster of 31% muriatic acid for every 6"x4" double sided 1 oz board. But not that you have to add it every single etch... this is kinda where it averages out, IME.
Curpric is also too opaque to see the board while etching. Once the board goes in, it changes from the light green mountain dew color to a very dark coca cola with hint of pureed spinach kind of color.
In terms of etching accuracy, persulfates are the best. Ferric is close second. And curpric is very close third. Relatively speaking, HCl and peroxide is quite bad. Notice that if you get the HCl concentration of curpric too high, the undercutting starts going crazy, like HCl and peroxide. To put it into perspective, if you etch a 12/12 1 oz board in a cupric bubble tank, and you leave it in 4 or 5x longer than necessary, you can end up with a rough looking 6/18 board that might work, still... or it might have a few broken traces. If you leave same board in HCl and peroxide and leave it in 2x longer than necessary, you will end up with a bunch of broken traces everywhere. At 5x, you would have very little copper left on the board, if any. In practical terms, this means with ferric and cupric, you don't have to watch the board etch and you don't have to worry about hot or slow spots, like you do with HCl and peroxide. With cupric, you just come back at a certain time when you know it's going to be done, and it will be perfect. If it's not quite done and needs just a few more minutes, you can come back in another 5 minutes or 40 minutes. It doesn't matter, hardly, either way. Things don't go south fast or far. I don't even set a timer when I etch. The first board in the tank might etch in only 20 minutes, if it's half oz, and I just don't care. Even it it stays in an extra hour, it will still probably be fine.
To get initial concentration, if you can't get peroxide where you live, it will take some time. You need a bubbler, period. Keep that going and before you put the copper in the tank of acid, heat the copper wires/scraps with a blow torch to oxidize the surface, at least. It might take several days to make without peroxide.
Compared to ferric:
Cupric has a very small store of oxider in it. The etch rate depends greatly on the amount of aeration you give it. An analogy is that cupric has a very small battery in it and relies on the power supply to do the work.
Ferric is more like a super big battery, which does the etching self-contained. But it eventually runs out.
HCl and peroxide is like an air oxide battery which consumes itself as soon as the battery leaves the factory, whether you use it or not.
So if you think you can just put some cupric and a board into a shallow tray, and rock it back and forth once in awhile, like with ferric, you will probably be disappointed, unless you are doing only small boards in a very large volume of etchant. It would probably be more practical for you to use ferric or HCl and peroxide if you don't want to bother with active aeration.