I am using a product, which is green moth paper, which also jkills dermestids. I haven't been to Germany in the last two years, but it was easily available in the drug stores (DM markets). It's a Nexalotte product.
I am normally overdosing it, cut the long strips into single sheets, roll these, and stick them into the box. This has killed exisiting Dermestid infestations, and so far was very successful. The fact that is is sold openly, and for cloth drawers makes me think that it is quite safe. Have been using this for more than 8 years now and never had any infestation. That said, since my main collection is in Germany, I also almost never open my boxes.
Best regards Ben
PS: attaching a pic of one of my boxes, you can see the strip in the bottom of the box. And yes, this is just one of my holding boxes, until I have enough species from a country/family to open a new box, hence the Madgascar-India mix-up.
Does it say on the box what chemicals it contains ?