Here is how to convert that gross old green hose into a modern hose using the original parts that come with a DX overpressure:
-You need to rip apart the green hose and keep the nozzle end that screws into the body of the regulator. You will see it looks like a hose barb. That hose barb needs to be saved.
-Buy something similar to this:
https://www.mcmaster.com/#5233k93/=1ea5vvi
This is 5/32" ID and 7/32" OD soft (~60 durometer) tubing. This tubing will fit the hose barb and the mouthpiece.
I've used tubing similar to this for 5 years on my DX overpressure. It works for me. Really, any soft, flexible, food safe tubing that is 5/32" ID and 7/32" OD will work.
-Place zip ties on both ends.
-Enjoy!
(Key words for search: DX overpressure, green hose, mcmaster, tubing)