I have used MaxMem, on both 4.2 and 4.5.
Main URL for BerryCoder - MaxMem is just one of the free products available:
BerryCoder
Direct OTA for MaxMem:
http://berrycoder.com/maxmem.jad
It removes many other things other than the pre-loaded pictures and
wall-papers. Be very careful and do a backup before using.