I've been using a rubbermaid tub for the last 10 - 15 years or so. There's absolutely nothing wrong with using one! I bet it's alot better than just taking your clothes off and tossing them into your truck. I never started using one for scent , I started using it for a place to keep my clothes.
You say they're not scent free , probably not , but try this. Take some cedar boughs and put them in with your hunting clothes for a few days. Before taking the lid off , stick your nose up to the tub and see what you smell , then take the lid off and see what you smell.