Can anyone tell me where this, comment #254117 and comment #254133 are from, please? I can't find them anywhere on his site and if there's another "outlet" of his oics I'd really like to know about it.

Artist tags have the letters in red on the list to the left of the image.
Welcome to Danbooru.

Thanks, but I said "I can't find them anywhere on his site". I know who the artist is and I regularly view his website but I haven't seen this images anywhere on there. That's why I was wondering where they were from.

http://cls.ath.cx/bang_you/contents.htm
Everything else on the site http://www.google.com/search?q=site%3Ahttp%3A%2F%2Fcls.ath.cx%2Fbang_you%2F
Remember that this is a commercial artist so most things on his site are just samples for his doujins and sketches.
I imagine like every other artist is "outlet" is doujinshi.