Here's something you might want to search for on the ecchi side of Iwara: 罰ゲーム. This search, as of today on my browser (Firefox 56, Windows 10) returns one result: this video by Tray Mendis. Not appearing in the search results for 罰ゲーム despite having it in the video title is this video by jugem1234, one of the most-viewed videos on the site.
Here's something else you might want to search for: 紳士ハンド. This search returns many results, but I still managed to find an omission: this video by foos, one of only two they ever uploaded (the other does appear in the search results).
What's up with that?