I'm confused, so you mean to remove the hose completely and soak it in a bath? Is it the inside that matters? Like could you just tape off one side and fill the hose? What's the issue that's being solved when you do this?
This video shows the location at 2:25 ish. I couldn't really see it by eye when I looked for it myself, but used my phone to take a video with the flash on to locate it. Then just follow that hose, unplug it, and fill it up for a good 24 hours.