Bad Ideas - Cleaners
Some cleaners are just best avoided...
Blood: Mrs Beeton recommends purified bullock's blood for removing grease spots.
Glo-fuel for model aircraft: various different formulae exist, containing methanol, oils, solvents such as ether, etc. Glo-fuel is highly volatile, highly flammable, explosive, very toxic, narcotic, contains ether which is a general anaesthetic from the Victorian era, and the fumes can be fatal. A powerful solvent blend, but the negative outcomes probably outweigh the benefits.
Mercury: Used in cleaning powders for silver in Victorian times. Mercury vapour is toxic, mercury is toxic to eat, and the mercury makes the silver weak and brittle. Not an ideal cleaner.
Saliva: While not one of the favourite household cleaners, its fairly effective, and is used in some households. Contains enzymes.
Turd: yes, really. Recommended for cleaning by.... Mrs Beeton again. To clean the char off scorched linen, she recommends: 1/2 pint of vinegar, 2 oz. of fullers-earth, 1 oz. of dried fowls dung, 1/2 oz. of soap, and the juice of 2 large onions. Thank god for the onions.
Urine: In Tudor times clothes were boiled in urine and wood ash on wash day. Lovely. Stale urine provides ammonia, and the wood ash reacts with grease to make a form of soap. It need hardly be said that one should not skimp on rinsing.
Hydrofluoric acid: removes most types of dirt. Unfortunately it also removes whatever the dirt is on, hands, finger bones, pretty well everything. Its difficult to store, as it attacks and eats even the most unreactive of storage materials. Store in glass coated in liquid paraffin, anywhere but here.
Petrol: From a Victorian book on servants' duties and helpful hints; "to dispose of bed bugs, wipe the wainscoting with petroleum spirit. Petroleum spirit can be bought from the chemist at 1/6d per pint. Do not do this by candle light." For anyone that doesn't know, petrol produces heavy vapour trails, which ignite ferociously from a distant flame. Petrol is still used to kill headlice in the 3rd world, and many have become human torches due to the vapour trail reaching a flame. Its also a carcinogen.
Cyanide gas: I'm not sure this qualifies as a cleaner, but cyanide is a traditional treatment for wasp nests. It works, as I can attest, but using it near bedroom windows is probably not wise. By the time you smell it, its too late.