All I know is you need to thouroughly and regularly clean your lint filter. If you leave it, it could catch fire. My neighbours house burnt down when they went out and left clothes drying in the dryer, due to dirty lint filter

Have to tried the smells paper sheets that you add to the drier?

Use a dry cloth to clean out all fluff, a touch of eucalyptus on it. Look at back of drier up against wall. Often very dusty and fluffy!!

Ensure that your lint catcher is cleaned. Rinse under water so its really clean and let it dry completely before putting it back together. When you use your dryer, do you use dyer towels? I use these when drying my towels and clothes that can get static, especially in the winter months and leave everything smelling really nice.
Another thing to look at is hanging on a wall to look behind and make sure its not causing any mould related issues behind it.