A few days ago I told you to go out and make an investment in some great kitchen knives. Once you've done that you'll want to buy a good wooden cutting board. These are the best surfaces for your knives. Of course you'll also need to have a plastic board for cutting meat that you can throw in the dishwasher. The only problem with the wooden cutting board is that it cannot be put in the dishwasher. I wash mine with hot soapy water after every use but when the watermelon tastes like onion it is time for something more. Here's what I do:
Wash your wooden board really good with hot, soapy water. While it is still damp sprinkle it with kosher salt. Then cut a lemon in half and use the cut lemon grind the salt into the board. The lemon juice and salt will become like a paste, keep working it around. Rinse with hot water and then dry. You should then condition it with food quality mineral oil -- you can find this in your grocery store.
Do this every couple weeks and your cutting board will never make your watermelon taste like onion.