You might be able to treat osmium so it is not noxious to you, but two
things may be a problem here.

Heavy metal disposal down a drain may not be allowed; and secondly,
treating chemical waste for drain dumping COULD be illegal in your area.
The latter may require some checking with your local wastewater treatment
plant.  
Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303