Was the sweet smell like cough syrup? If so, he was definitely cooking. And I can guarantee that everything you received is coated in its residues.
Keep the room well ventilated. Those chemicals can cause respiratory infections IN HUMANS. Be very careful with your electricity procedures. If you can smell it, it's very flammable.
In the meantime maybe a sealant on the racks for now could help contain the chemicals. But again, you'd have to be careful when applying that around the snakes.