It "isn't used to to mean a arduous task in general" says who? The OED defines it as a "troublesome business, a piece of hard work" with examples of that particular usage going back to 1964 in the Economist, who I presume wouldn't have used it unless their audience would understand. Pg has provided contemporary examples from the web at large using it in this fashion as well. Also the original German doesn't mean the actual journey but the act of dragging or being burdened so I don't see how this usage is likely to be at odds anyway.