that's the exact same way i defrosted my minifridge's freezer so all the water went into a bucket. Very clean - the liquid only falls off the lowest part of the paper towel. just set it up and walk away for a few hours. Except i'm sure dripping a radiator dry takes quite a bit longer.
'06 Z4 3.0si: Bright red, dream red extended cowskin, M seats, power seats, butt toasters, bluetooth/assist, SP