up the wazoo/kazoo

[Sam Clements]

If I missed a discussion of these terms as they relate to "anus,"  all I can plead is that I searched.

RHDHAS lists "kazoo" to mean "anus" from 1965.  I tend to think, at least in the US, that the term "wazoo" has, in the last 10-20 years,  overtaken "kazoo" in phrases such as "blow it out your wazoo" and "up your wazoo."  

Since we can't read Vol. III of RHDHAS, can anyone cite when "wazoo" became the term of choice?  

Along with "wazoo" we would also like to know about the use of "...out your ying/yang."  Again, no Vol III.