After I use my tips, I always make sure to let them soak in hot soapy water and then scrub and rinse them well. But, I've noticed they still have some kind of residue on them.

How do I get them really clean?

Hot, soapy water plus vinegar is my go-to solution to this. Vinegar is one of the most wonderful and underappreciated cleaning products in the universe, as far as I'm concerned. I also wash my bowl, beaters, spatulas and storage containers in it when I'm doing anything with egg whites, like royal icing. And then I clean my floors with a vinegar-and-water solution after a long and messy session of caking. The best!

hmmm....vinegar, huh? I'll have to try that sometime. I gave up on handwashing those things and dump them into a little basket I have in my dishwasher. That works great if you happen to have one.

A little trick I learned a few years ago is to put the tips in a bowl, cover them with water and put them in the microwave. Heat the water to boiling. It works great. Sorry I can't remember if I got the idea from Cake Central or somewhere else.

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.