This is a good time for a bit of thought about how bad things are!
Got so much algae that you are totally starting over and that means killing algae and then maybe the filter, etc. has some fungus that may have grown while it has been shut down? At that point, I look at the soft media in the filter and try to decide if I want keep it and sterilize the whole thing or just ditch the soft, cheaper stuff. Any known diseases in the tank which you might also want to make sure they are killed? What about the sub? Is it a keeper item or just cheap stuff that is better ditched? Sand is pretty cheap and maybe not worth the work to soak and then dry?
So If I want to really kill it all and make sure there are no snails, fungus, snakes or crawdads, I do a pretty heavy bleach soak and do it simple. I add 1/2 to full cup of plain, unscented, no color bleach and fill the tank. Just the cheap stuff with nothing added!! Then I start the filter and let it all run through to get all the parts sterile at one shot. Let it run over night or so until you get back to it and then carefully drain the bleach water somewhere like down the drain so that it doesn't kill the grass in the yard, etc. All during this, make sure not to get bleach water on any good clothing that you don't want holes or white spots!
Once drained, then I almost always need to scrape algae and clean the glass good, rinsing as I ggo. By the time I get it all rinsed, drained and rinsed some more, most all the bleach and chlorine are gone so that it has stopped smelling. If I still smell chlorine, I may let it dry to gas off and then I'm ready to start rebuilding, recycle, and restart. Too strong on the bleach and you may find the soft media needs to be replaced as it may fall apart. If not wanting to risk that medai and sure there is nothing in it like disease or snail eggs, I pull it out before running the bleach through.
Not a fun thing but I look at it like my dishes that I eat off. Not fun to wash them but I sure feel better knowing they are all clean and safe when I start eating. It removes lots of those little doubts that can show up later.
Vinegar is good for softening any hard water deposits or wiping the glass down.