Sorry to hear you are having such an awful problem with your mats. i have 2 olfa mats one is i think 17 x 24 and the other is 17 x 17 which is a rotating one and neither of mine have stunk. I am just a bout to go and buy a small one for piecing so will make sure it doesnt smell. I think the bicarb idea is a good one..maybe even leave a box of bicarb opened on top of the mat might help..put in a few drops of essential oil and maybe that will disguise the smell and dont forget to open your windows etc.