Perhaps some work needs to be done before you can actually use these items as hiding places. And to avoid someone (i.e. children, visitors) from accidentally discovering them is another challenge.
If you really have lots of valuables at home, getting a safe box might be a better idea than stuffing your pillows with jewelleries. Unless you actually sleep better that way. Manalah tau kot2 lagi lena tidur berbantalkan intan berlian :-p