A: What you’ve discovered about aromatic cedar is common. The great smell doesn’t last forever. You didn’t get a bad batch of cedar. The decline is caused by volatile oils that dissipate all too soon.
One way to re-establish the nice smell is by sanding lightly. This exposes new areas of wood that still hold those precious oils. Trouble is, sanding causes dust, which is never good anywhere in the house. But compact, hand-held sanders are getting better and better at capturing dust these days. You’ll still need to remove all the contents of the cabinet to keep them clean, but most of the dust won’t see the light of day. Currently, the cleanest hand-held sanders include porous plastic dust canisters that clip onto the machine. That’s me to the right using one at my workbench. If you want to go completely dustless, place a shop vac hose in the cabinet and switch the vacuum ON while you’re sanding.
If you’d rather not sand at all, there’s another option. You can apply cedar oil as a liquid to the wood with a cloth. Google “cedar oil” and you’ll find a number of brands and sources. One interesting thing about aromatic cedar wood is that it’s getting much less common in stores. Years ago it was easy to find, but these days it’s almost a special order item if you’re building something new. Quality is lower and the boards are thinner than they used to be, too.