Here is some more info on scent items from a different SAR handler:
http://webcache.googleusercontent.c...ent+items+be+handled&cd=1&hl=en&ct=clnk&gl=us
What makes a bad scent article?
A bad scent article doesnt have the scent of the subject you are looking for, or has been contaminated with a competing scent that confuses the dog. This contamination could be from residual sources, scent falling from the air or transferring from another article, or direct meaning someone other than the person you seek touched the scent article. Example of bad scent articles: Clean laundry. Shared clothing / linens. Item handled by someone other than the subject, something that has not been in contact with the subject recently.
Many times a scent article is collected by a family member for the teams to use, without knowing that this is not an accepted practice, so it is often the best to try to obtain an item yourself, but always thanking them for the effort!
How do I collect scent guide/article?
When in doubt, don't. Let the dog handler collect it or a trained member of the search team that has been taught how to properly collect the scent articles without contaminating it too much. If the situtation dictates that you must collect one, choose an item that you believe will contain a large amount of the persons scent. If the area has been thoroughly contaminated by previous search efforts or other family members, look under furniture and between mattresses. Take precautions to avoid contamination of the item as the more scents that are on the item, the more the dog has to work through to find the correct scent of the missing person. Remember that the person collecting the article is contaminating it! Handle the items in as short a time as possible; avoid leaning over the item. ALWAYS use gloves (i.e. latex) especially if you have to spend time sorting or moving items around to find a suitable article. Use clean tongs / tweezers to pick up the item if possible as it will keep the item as far from 'your' scent rafts as possible. If possible make multiple scent guides form one item by, cutting it and bagging them separately ( if the item is NOT needed by Law Enforcement as evidence ). Most search teams recommend that you use a zip-loc style bag ( without perfumes ) as they are small and see through. Seal bag as soon as possible after collecting item.