Ok, it's rules legal, but I still think it's cheesier than a box of Cheez-its wrapped in a pizza and dropped in a vat of Velveeta somewhere in Wisconsin. Not because I don't want clerics healing outside of combat, but because of the way the system is set up.
Jump off a cliff, lose 90% of your HP, climb back up, jump off again and you're vulture food.
Jump off a cliff, lose 90% of yoru HP, climb back up, take a 5 minute rest, jump off again, and you're fine having only lost 90% of your HP again.
4E healing is cheesy period. Just grin and bear it.