Para-Moth (paradich-lorobenzene) is used to control wax moths. I've put my empty supers outside this year due to lack of space in the barn and some wax moth issues last year - stacked about 4 or 5 high on pallets and top and bottom closed off - then you put the moth crystals on the top super - I put mine on a paper plate - about 3 oz and close it up. The gas produced is heavier than air and will escape. It's a strong smell much like moth balls - well, it is moth balls.
The supers will be fine all winter and I'll check again to replace the crystals when needed. I'll have to air all these out in the spring before using on the hives - like you do your winter clothes if you've had them in storage. This is the only chemical I use for my bees but wax moths are nasty and will destroy foundation in a minute.
Of course, it was cold as Moses last night, so any wax moths were probably killed by the cold but better safe than sorry.
