Vassily Alexeyev (former world record holding olympic lifter) used to walk 1000 steps in the sea after each workout (he trained in his backyard a lot.
It has some merit but will mostly strengthen the rectus femoris and psoas, which is not necessarily something you want. And I'm not sure that the resistance is high enough to have a significant effect on growth.
It probably works for improved recovery, but it is doubtful when it comes to building muscle. Might as well simply go swimming.