How to touch every bit of a block of memory ?

To do sanitization of a block of memory , i came across a technique today

.The Algorithm is as follows

a ) Generate a random string ( called RANDSTR ) of n bytes
b ) Get 1's compliment of that string ( ~RANDSTR )
c ) Fill the buffer with RANDSTR 
d ) Fill the buffer with ~RANDSTR


This will make sure that this touches every bit and might sanitize the stuff