Use a new needle every time you shoot up. In New York State you can get clean needles from a needle exchange program or from a local pharmacy without a prescription.
Step 1: Draw clean water all the way up into your set, shake it and squirt it out. Repeat this process three times.
Step 2: Next, repeat this process twice using full strength household bleach. Leave the bleach in for a total of 30 seconds or more. You can also take your works apart and let them soak in a bowl or pan full of 100% bleach for 10 minutes.
Step 3: Finally, flush again three times with clean cold water (cold water rinsing prevents blood coagulation).
Step 4: Wipe the cooker with bleach-soaked cotton and rinse with water. Throw away any cotton used for shooting drugs. NEVER share or reuse the water, bleach, cooker or any parts of the cotton.