Anything airtight will stop the smell getting out it is true. You can use the glass beakers with bungs and levers, or the airtight herb containers.
However as GL points out, contamination of the outside is a problem. Soak the container in boiling water and rinse it thoroughly, and wash your hands!
Also if you smoke weed you are likely to get picked up by a sniffer dog anyway cos u will stink so a better bet would be to have your drugs in a stash pocket sewn into your pants and tell the police that you had a spliff before you came out but have nothing on you, they will do the bog standard street search and believe your story
Another fairly safe method is to bag up your stuff and put it inside a container of liquid. For example, a bag of weed inside a bottle of shampoo is pretty undetectable, and no copper is going to pour it out looking for drugs
Also be aware of what you have and how smelly it is. If you go out with acid and ketamine it’s unlikely and sniffer dog will pick that up. Coke and weed however are the most commonly searched for.
