An understandable concern people have about purchasing second hand is cleaning those secondhand items. I am aware of the importance of cleaning things that come from a source you may not know; this is how I clean secondhand items that come into our home:
For all cloth items - These go through the wash. Usually twice. If I purchase them from someone I know, they get washed once. Clothes, cloth books, etc. that are from garage sales or thrift stores go right into the laundry pile before being used.
Toys/Dishes/Things that Fit in the Dishwasher - They get hand washed and then run through the dishwasher.
Large Toys or Things that Can't Be Washed as Listed Above - This is where the rules get broken - I whip out Clorox wipes for these. Since I cannot know the cleanliness of the prior home, I want something strong to clean the item! This is especially true if my daughter might chew on the item. After using the Clorox wipe on them, I am sure to wipe them down with simple water and a cloth to clean the Clorox off.