If you're gonna remove and reseal the front timing cover, then might as well go the way that Hans described since you'll have all that clutter off -- and yes, the MB sealant, although pricey, is still the best stuff.
IF you're lazy like J.H. and I
try his method. Buy 2 hoses though just in case you mangle the first one. They're pretty cheap.
'91 300E, 209k miles