I use a small sauce pan and a strainer.
1. Boil tips and couplers in water.
2. Dump in strainer, rinse and add more water, bring to a boil again.
3. add 1 or 2 drops dish washing liquid. Keep an eye on this, it will boil over quickly.
4. Rinse thoroughly, add more fresh water and bring to a boil again.
After it comes to a boil, strain and right away, sit on a few folded paper towels to dry.
The heat dries them almost instantly.
I do this as I am cleaning up my mess. It get's all the butter cream out of the tips of the smaller pastry tips, and keeps your pastry tips grease free. Grease free means germ free!
*This cuts the grease and keeps your couplers very white.