Rico's "Sauber Sepp - Chain Lub Spray Guard" inspired me to create this bit of "elbow macaroni."
https://www.printables.com/model/266518-sauber-sepp-chain-lube-spray-guard

The problem I have cleaning my bike's chain is spraying the inside of the chain. There is just no easy way to reach it, even from the other side.

My first thought was to remix Rico's design, replacing the shield with a guide that would force the spray tube into a 180 degree curve. But when fitting a spray tube onto a test print of the 180 degree curve, I realized I didn't need anything more than the noodle.

The spray tubes on my two favorite brands of chain lube different sizes. One is about 2.15 mm, the other is about 2.25 mm. So I made each end of the channel different sized, one to fit each spray tube.

My final design change was to make the outside of the noodle hexagonal instead of round. This makes an easy print with no supports that doesn't sag.