I would defo not advertise it. I would mention it when the client makes the booking if need be.
Why not advertise it? I can definitely see advertising say swallowing but only saying 'Oh, yes, it's an extra ?50, did I forget to mention that earlier' when you're talking to the potential client is going to lead to a lot of suddenly terminated calls. So the options are either don't mention them at all in advertising or add the price. I suspect it comes down to the question of whether or not you actually want to do them. If yes, be up front. If not, then responding to direct enquiries that you'll do it for extra ???s would be more ok.
Oh, if you're going to advertise rimming, you need to be clear as to whether that's giving or receiving or both...