I would totally get pee pads.. you have to watch him and know when hes about to go pee then put him on top of the pad and praise him. If he makes mistakes tell him no.. then put him on top of the pad and praise him. Eventually your dog will learn! For the smell.. if you have bleach safe floor i'd use clorox and a mop, then dry it off with old unused towels..
saw dust is very absorbent and free from alot of timber yards, mills etc. just bag it up and bin it ! i would recommend cleaning the lino with a pet friendly dissinfectent (sp) because dogs will pee where they smell pee....shouting at a dog for peeing can have a reverse effect, but training him out of it shouldn"t be impossible.
Maybe it's just me but I think at 5 years old with a medical issue scolding him will do more harm than good. He probably feels bad about it already and since it's a medical issue he can't control it's like scolding him for just being. Gentle positive guidance to use the pads until this issue is resolved is my recommendation.