I'm not judging that the "best practice" 30-40 years ago was right or wrong.
But certainly everything has change a lot since, in this 30-40 years. Science, new researches? So shall we follow and accommodate to these changes or just simply stick to the practise which was ok 40 years ago, but might not work well today?
I am dealing with people on a daily basis who believes in the "that's how we've been doing this or this or... for generations" practice. And now we put a transponder to the cow's stomach and I can tell everything about her... not to mention from my phone lying in the bed...
So personally I trust in science and technology so accept the change and what it brings into our everyday.
If it is checking lymph nodes to control and monitor tb, then I do it.
If studies say that the lead dust contaminating 500mm around the wound then I believe it, however I can't see and imagine how that happens?
So when science says that using water for cleaning a carcass is spreading the contamination, then I also believe it. I might be naiv but hope you see what I meant to say?