Do you want to copy and paste the MSDS’ for bleach, oxyclean, and the other chemicals mentioned in this thread for balance too?
From your link:
“You can get a lethal dose of chlorine by taking a few breaths of it at a concentration of 1 part per thousand in air.”
Ok it has nasty effects below that, but 1000ppm is a good starting point for working out how nasty 1tsp of each in a bucket is.
Assuming all the vinegar and bleach react.
Sodium perchlorate 3% solution (household bleach) molecular weight 122.5 (chlorine 35.5), so in the 3l bucket we have 0.043g of chlorine.
Assuming you mix it in the downstairs toilet as the smallest room in your house, say 1m wide, 2m tall, 2m long, 4m2 in total.
0.043g of chlorine (if it was a gas and not in the water) would give a concentration of 10ppm by weight, 1% of the toxic level, if it was a gas, and if you did it in the smallest confined space you could find.
You can kill yourself with it, but it’s not going to be by following those instructions.
You can also use phosphoric acid, sounds nasty, but it’s a great sanitiser at about 1/4 the concentration Coca-Cola use it as a flavoring.