Hi i found this quite complete guide on thumblr (https://blindjaw.tumblr.com/post/161412537989/i-just-finished-writing-and-illustrating-this ) who is iven in several languages.
About the taste, is usually tasteless afer cleening, but ass mucoses can have a bittersweet taste not unconfortable at all. I use to think was lube traces haha
Have fun!