In The Phantom Menace, Anakin talks about having a bomb inside of him and, should he try to escape, Watto can simply blow him up.
SHMI: All slaves have transmitters placed inside their bodies somewhere.
ANAKIN: I've been working on a scanner to try and locate them, but no luck.
SHMI: Any attempt to escape...
ANAKIN: ...and they blow you up...poof!
Did they ever remove this bomb or device from Anakin? Did Watto still retain the ability to blow up Anakin?