I know this will sound severely alcoholic but for years I carried around a corkscrew just in case. I was kind of traumatized by how I managed to buy a bottle of wine when I was 15 (in Germany wine is legal from age 16) but I had no opener so we tried for hours to push the cork inside with a stick and I did not want to repeat that. It worked but the cork broke and we had very crumbly wine. Don’t recommend it.