Another dumb question

Gang,
On some model locos I've seen (and almost universally on detailed logging engines) there are small, "garden" sized hoses draped over the domes or on the running boards / hand rails. I've always assumed these hoses were used to clean the engines, but have no idea where they would be connected to get cold water under pressure. As almost every steam loco model I've ever seen has a globe valve with what would appear to be an open pipe pointed straight up on the steam dome, might the hose be connected there? Or is all the water up there either very hot or already steam?
Where would that hose be properly connected? Thanx, Gary