Okay... this little one should keep you occupied for a while. Sex toy inventor in the future... NOT for the faint of heart:
http://www.mangago.me/read-manga/gingaku_hakase_to_marmot/
This one is just ridiculous and has no real plot, but I find it really entertaining ^^
http://www.mangago.me/read-manga/oshioki_gakuen/
This one is so random and weird, yet funny.. ^^
http://www.mangago.me/read-manga/vibrator_company/
Koisuru Omocha is a good one.
i rlly want to know lots of sexy yaois which have a lot of vibrators, dildos and sex in.........