That sounds like yeast to me, especially the smell and sliminess. At this point it will be very difficult to rectify, especially since I see this is a gouda. I have never seen an oiled gouda, nor would I try it becasue of the high potential for yeast problems. Gouda is a very wet cheese and has lots of food on the surface for yeast to grow. This fact, coupled with the relatively high rind pH of gouda early on in the aging process, is the reason it is normally waxed.