I think your sarcasm is a part of you. If your Dominant doesn’t like it, then you have to be willing to try and change for yourself. It’s a habit, a behavior you have had for a long time, so it’s expected that time is going to be a factor in changing it to something else that he finds acceptable.
A lot of people use sarcasm as a defense mechanism when they are scared or nervous. If this is the case, just change the witty comments into real statements. Tell them you are scared, or nervous. You might be surprised by their reaction.
When I tell SG I am scared he says “Good, now bend over”. I just want him to know I am reluctant for a reason, not because I am intending to be a pain in the ass. This helps me a ton because now I know that he knows I am trying, and fighting against my own feelings to make him happy. You would be amazed how much that can make a dominant soar.