I just bought one of these for my sister who is due to have her first baby next month. I have no idea if they work or not but I figured it can't hurt to try. I bought it from Toys R Us for around $50 and at the time it came with a change table caddy for free. All my sis needs to do is replace some kind of anti-bacterial thing in them every few months.
Sorry I wasn't really of any help.