Oh, that's a shame
If you get an experienced judge you should be OK but of course some local judges are only used to the local breeds - we get this problem with our Old English Goats, they aren't the same as the big milkers.
Fortunately for us, Rough Fells are (at the moment) shown pretty much as they come out of the field though we all wipe their faces and horns with baby oil and water to make them glisten
There was some talk at the last show of starting to use fleece-rinses like they do in some other breeds - please not, we don't have that sort of preparation time nor facilities.
As for what the humans wear - your cleanest pair of waterproof trousers and your working boots, polished