Man, you would think that Olfa would do something about their manufacturing process to eliminate this problem! It seems most everyone has had a cutting mat that smells like skunk or worse!! This problem goes back at least to 2011!! I can't even stand to walk by them in the store.
If it was me, I would return those mats and look for something else. If it smells in the store, it will smell even worse when it gets in a smaller space. I had a couple of small ones that smelled and after two years of them living on my back porch and too many "fixes" to count, I just trashed them. Never ever got that smell to go away.
http://www.quiltingboard.com/search....rchid=13415318