Hi yea right

I would use standard PVC conduit and boxes, it's cheaper than garden
hose and more impervious to cuts.

I doubt if your going to be able to 'push' a coax through a hose, or
even conduit for that matter. You will probably have to 'pull' it
through using a fishtape.
As the distance increases, so does the friction against the walls of
whatever you are pulling it through.
One cannot even pull a piece of romex through 15 feet of PVC without a
fishtape and some wirelube from your local electrical supply house.

TTUL
Gary