I can attest that DallasRain's milkshake is awesome! It's a great way to get edged.
I like having stuff up my butt, but for some reason, when I cum that way, my cock feels kinda numb. So I like to have something up there and/or prostate massage, but then take everything out. That makes me more aroused than ever.
One thing I have not done, that I would like to try is to just continue with a prostate massage until I have a "prostate orgasm". I've heard it is awesome, but I've never done it.