Controversial 'contraband watch' in California prisons is invasive yet often ineffective

California uses a controversial method to recover contraband from inmates believed to have swallowed it or concealed it in body cavities.

The searches are often called "potty watches."

Inmates are handcuffed and shackled for days or even weeks while guards watch around-the-clock until nature takes its course.

Potty watches have been used 1,200 times in the last 2½ years, producing results only about 41 percent of the time. A state inspector general found procedural problems in nearly half the cases he reviewed.

Prison officials say the watches are necessary to recover weapons, cellphones and notes passed among inmates to coordinate illegal gang activities. Some recovered items seem bizarre: a can opener, hearing aids and an entire electric tattoo kit.

Other large states have less restrictive ways of searching for contraband.