Image: Empcon54
The United States Practical Receipt Book, first published in 1844, offered its readers instructions on how to make all sorts of things and included references such as how to discern the quality of beef. It also offered this tidbit in between mentions of liquor and plaster:
"Baudruches, or Condoms
Take the caecum of the sheep; soak it first in water, turn it on both sides, then repeat the operation in a weak ley of soda, which must be changed every four or five hours for five or six successive times; then remove the mucus membrane with the nail; sulphur, wash in clean water, and then in soap and water; rinse, inflate, and dry."
But that is only the beginning. Read the remaining part of the tutorial at i09. You know, just in case you run into an occasion in which you need protection but find yourself without any.
Of course, you could soak them in mercury between uses (reportedly done by French nobility back when) that would help.