You can, but...
1) if you're using whole hops, you'll want to filter the hops with a screen/bag so they don't clog the 3/8" line
2) you won't get much flow through the 3/8" line, so not much whirlpool effect. you'll want to really get the whirlpool going w/ a spoon or paddle.
The potential advantage I've seen to recirc/whirlpooling is that you get the entire wort below DMS producing temps quicker. Other than that, I don't see any.