I didnt read the TH article, but new AMD CPUs, like the the Sempron cores, cannot be unlocked. Period, not by shorting pins, not by shorting bridges.
My Athlon XP2500, which is several months old, cannot be multiplier unlocked.
the XP2500 Mobile is by default multiplier unlocked. (This is hope a mobile computer...laptop... throttles the CPU speed) If you have a motherboard that allows you to change the multiplier as well as the FBS (most allow FSB, few alow multiplier) than you can underclock the CPU causing a dramatic drop in power input (and heat output)
Make sure you get a Mobile chip... forget the
PR #... doesn't need to be a xp2500, could be an xp2100...just get a mobile and you will be fine as long as your motherboard supports multiplier changes.