Adopt a white trash management style.
Do pasture turnout with sheds instead of keeping the beasties in a barn. That way you aren’t having to pick stalls and push wheelbarrows full of wet bedding around. Break up the manure piles by dragging an old piece of chain link fencing around. (This is your excuse for hanging onto that old lawn tractor with a bent mower deck. It can’t cut a straight line, but it’s perfectly good for dragging things around.) Substitute a couple of old Christmas trees lashed together if you don’t happen to have old fencing.
Use an old cast iron bathtub for water. Pull the drain plug and let gravity take care of removing the water for you. Scrub with a long handled brush and fill with a garden hose. A cast iron bathtub is too heavy for you to move, but it’s also too heavy for the ponies to move. The thing will still be sitting in your pasture breeding mosquitoes after the rapture has taken all good rednecks to heaven. If you don’t believe the rapture is coming for you, you can instead prop it on end and put a statue of St Francis or the Virgin in it once the ponies cross the rainbow bridge.
Keep the ponies barefoot. Less gunk builds up on their feet, so you can get away with picking the feet less often. If pony is really cooperative, you might be able to teach it to stand with its foot propped up on an axle stand padded with an old towel or piece of foam (secured with duct tape, of course.)