Hi Mark,
50 years ago me and a friend would lay the wheel on the ground with a small diameter tire under it,lube the rim with "green slime" (industrial hand cleaner), link arms and stomp the tire on with our engineer's boots.
I swear the tires we had back then went on a lot easier than the tires you get today.
I suggest that you go to a tire shop and scrounge a cupful of their special tire soap, it seems to work far better than the hand cleaner or dish soap that most folks use for their DIY tire installations.