I've worked with ferric chloride, perchlorate, and cupric chloride... sticker, pen, and laser-toner-transfer. Jumper wires and via plugs. All of those may work, to varying degrees... but even with decades of experience, none are nearly as good as a professionally-made OSHpark board. So all of those chemicals have been (safely and properly) neutralized. Stickers, discarded. Transfer paper, collecting dust. So much easier and nicer with a turnkey fab.