I think we all know there aint one right way or wrong to train dogs.
There's more methods than there are dogs I reckon.
Myself, I've had Britts for over 25 years now & never had washing pulled off the line, despite never having to teach the dogs not to.
On the other hand I've seen guys teach their dogs & in the process create some bloody aweful problems.
If i dont have to teach my dogs not to grab the washing off the line, then there's never problems arising from it.
It's a matter of avoiding problems rather then having to fix em.
Washing..........................................................................Dog.
No problems in-between for me.

In regard to what's right & what's wrong we need to think of it from the dog's perspective, not ours. What they perceive as right may not be what we poerceive as right.
Dog's generally pull washing off the line because, no matter how hard you wash some clothes there's always a lingering scent of the owner still in em.
Dog pulls washing down & what do they inevitably do? - lie on it.
Why? - dog wants to be with you & can't, so your scent offers security.
Dog actually thinks pulling the washing off the line IS the right thing to do.
Scold him for it & we start to confuse the dog.

I also cant see how teaching a dog not to pull washing off the line is 'working for you'.
I'd say that's actually creating more work for you.
Just something else to teach that has noithing to do with hunting, whcih is why we got the dog in the 1st place.
I've had to teach my dogs to hunt. Nothing else.

I also dont teach my dogs not to beg for foods from guests at BBQs, nor to not run across roads.
BBQ starts up - dog in pen.
Road nearby - dog called in & put on lead.

All that's in the heads of my dogs is huntin'.
That's the way I like it.

Now if the washing blew into the dogs pen then that would be a whole nutha ball game ;-)