We recommend that you use unscented dish soaps as all scented soaps will attach to the oil residue on your silicone dishes. To remove the residue please try using a fresh lime or lemon and rub it all over the silicone, let it stand for a few hours then wash it off with hot water. If you have a vegetable scrub brush (hard bristles) the silicone needs to be scrubbed quite hard. 

If you have been using cascade in the dishwasher the smell may be hard to get out.