Getting extremely sick of wasps in various places, gasoline(petrol) is a great eliminator, and normally I fill a few tablespoons into a yogurt cup and just splash it on their nest. Goes without saying do NOT do this near flames or electrical and wear PPE. Gasoline swells rubber like mad which is what the plunger seal is made of. I needed a way to use a nitrile O-ring, so I came up with a design that just slips on to the existing plunger handle, and is printed from PLA, which is not affected by fuel. Applying a bit of petroleum jelly helps slidy-ness. Simply pull the plunger to fill with fuel, take it to your favorite wasp nest, and you get about a 10 foot accurate range. This can probably be used for hard to start engines or other chemicals for other purposes. Simple to print.