Nobody got that stuff about cleaning fluid?!
Okay. Deep breath...
In The Moonbase
, Polly, Ben, and Jamie, imprisoned in a medical bay by the Cybermen, decide to try and fight back. Jamie suggests that back in his day, witches were sprinkled with holy water. Polly, who's been doing her nails, hits upon the idea that, if nail varnish is a kind of plastic and can be removed with something like acetone, then maybe it could affect the Cybermen's own systems. They mix up stuff like benzene, ether, and acetone, put it into fire extinguishers and squirt guns, and christen it 'Cocktail Polly'. It kills the Cybermen rather effectively in the Moonbase, and on the lunar surface, although a spray wouldn't work, a thrown bottle does.