I wish I could find a more peaceful way but I can't. Each time I think I find a good solution, I realise that I can't get the ingredients here...
So any advice on the cleaning agents?
In hydrogen sulfide poisoning, as little as 400 ppm can cause unconciousness, in 1000 ppm death occurs within minutes.
Symptoms of H2S poisoning: mild to severe throat,eye,lung irritation, nausea, headache, vomiting, loss off coordination, loss off memory, sudden collapse, respiratory paralysis, seizures, coma and death
Fatal amount: If the cabin volume is assumed to be 3.300 L, mixing 120 mL of each lime sulfur and acid would produce 1000 ppm hydrogen sulphide.(the lethal amount). If we keep in mind that people who use h2s to suicide mix several containers of this chemicals, So the amount of h2s produced is 20-30 times the lethal amount, which creates an extremely dangerous environment for first responders and bystanders.
In a h2s experiment inside a car showed that 1 liters of each product produced 15000 ppm hydrogen sulfide(15 times the lethal amount!) and it took 4 minutes for h2s gas to reach concentration above 1000 ppm.
2 liters of each product is advised to guarantee death and get unconcious faster. Remember that when acid reacts with lime sulfur, the liquid inside the bucket will pour out, so make sure you wear thick gloves, welding goggle(to minimize the eye pain), a coat, large boots, and large leggings. Hydrogen sulfide will cause frostbite to skin if touched, in short wear safety equipment. You can just go to a medical store and buy these items.
Unconciousness might occur 1-5 minutes after mixing chemicals.(making a guess) That is because it takes some time for the gas to reach lethal concentrations.
Note: Sulfur concentration should be high enough to react with hydrochloric acid. Adding dandruff shampoo to acid will be a waste because dandruff shampoos only contain %1 selenium sulfide. Using strong enough concentration is advised.
Definitely take it outside, maybe in a car, posting caution signs on windows would be good.