I have a Kampa push me pull you for my awning and the not too flexible hose broke last weekend. It is not available as a spare from Kampa ! So, I trawled my man shed and found a spare bit of sink waste pipe from when I rerouted mine. It fits and is much more flexible than the original, and looks to be stronger as well.
Thanks to my dear old Dad for teaching me to mend not throw away :)

My kampa hose has split in several places. Interested to know how you attach the end bits securely to the piece of waste pipe. I was thinking of using a piece of hose pipe.

I used the convoluted waste pipe I had spare and warmed the ends in hot water before I pushed them on. As it cools it shrinks a bit and seals.