I shadowed abroad (don't ask me where; it shall not be named) at a private dental office for 50-60 hours. It was supposedly the most respected dental office in the town where I was.
I saw some horrifying stuff there. Really really poor infection control and personal safety standards. I feel so bad for the patients who have to use this office. Made me appreciate American standards much more. Never again. I'm surprised I made it out of there without being the victim of a needlestick.
Seriously, if you tried to pull what they were doing here in the U.S., you'd have OSHA banging down your door so fast.
I didn't list it on my application since I had plenty of relevant US experience. This was mainly for enrichment/exploration.