I am the least expert on the board, so take my advice with a grain of salt, but goudas are waxed, oiled, bagged, or painted before any nasties rear their ugly heads. The problem with wax is you can't see problems underneath. I waxed two of my three goudas, and one of them was caught leaking (weeping whey) after a month in the cave, right through the wax. You could smell something was not right. The wax came off, the problem corrected, and yesterday I cut it open after 11 weeks of affinage. My third cheese, my best one yet!
On my natural-rind cheddars, I brush the mold off weekly (or as needed), and take a salt water wash to annihilate anything blue, black, or grey. Orange, yellow, or white gets a free reign.