If the hose is 5 years old, like you said it might be a waste of time. At that age, my experience was the flexible material between the rigid spiral ages out and will begin failing all along the length of the hose. I was going to do what you are suggesting, but once I tried removing the fabric cover I realized the hose had become a sprinkler along most of its length.
You can buy a new hose without the fabric cover for much less, it is Thetford part 97521, currently under $90.
Thetford 97521 Hose Kit https://a.co/d/i1ktHRU
Be aware you may not be able to re-use the fabric cover from your old hose, the diameter might be too small to fit over the glued on cuffs on the new hose, at least that was my experience. I purchased this larger diameter cover which will fit over the cuffs.
Tompkins Industries 039-NHS225-25 Nylon Protective Hose Sleeve, 2.25" ID, 25' Length, Black https://a.co/d/3DsIjHf