What Is Going On In There?

We have a shower problem. One of our shower problems is that there are 5 of us using the shower. But, aside from that, the shower has a slow drain. Lately, you have to stop showering because the tub is filling up rapidly. So, today I decided to go to the hardware store to get "Drano" or some Italian version of Drano. I found one on my map and went on a search for it. It's pouring rain outside, and i'm out there, dodging umbrellas and puddles, in search of this place. I finally come upon a store that says m-whatever (the word that means hardware store, I can't remember it now) and I go inside. As soon as I open the door, I know i'm in trouble. There is a tiny room that resembles more of someone's disorganized garage than a store, and you can't tell what is for sale and what belongs to the shop owner. In the middle of the room, two older women are sitting on chairs having a discussion. In fact, at first I thought maybe this wasn't a store at all. I kind of wanted to turn around and run outside (you know, have a "do-over") but I couldn't. They were staring at me, I was trapped. So I said my favorite phrase, "Parla Inglese?" and they said, "no." So, I start doing my I-don't-know-the-words-stammer, like maybe if I say, "Ahh. Ah. Ummm. Hm. Ummm," the Italian will just come to me. It never comes to me, because I CAN"T SPEAK ITALIAN. So, in my brilliance, I say, "Drano?" No response. Blank stares. Silence. I launch back into the the stammer of ah's and um's and one of the old ladies says, "Verbo." Meaning, to tell them a verb. I'm thinking, If I had one lady, i'd have given it to you by now. So, I look around, say Grazie, and leave, heading back into the storm.
To fast forward a bit, I end up finding another hardware store that resembles more of a store and a man who spoke a little English got me a bottle of something used to unblock drains that are clogged.
Feeling very proud of my new drain stuff, I go home and start cleaning the house. When it comes time for the shower drain I open the bottle and start to pour the stuff in, not expecting anything unusual. But the second the stuff hits the drain it starts fizzing and I can hear it fizzing and burning stuff all the way down the pipe of our ancient barely standing plumbing system. I call Cara into the bathroom to hear this stuff eat through "absolutely everything" and we're both just standing there, listening to the weirdness. That's when I started to see some "smoke". Now, I don't think it was actual smoke, but whatever it was, it was a visible gas coming out of the drain. And then came the smell. Burning hair smell. I have no idea what was going on in there except whatever it was involved an obviously corrosive and insane acid mixture that I don't think they have any business selling in some weird hardware store. Now our entire house smells like burned hair. All I know is that drain better be faster now.