M.M.
My daughter does not have sensory issues, but she was afraid of the potty. I did not force the issue, but instead her and I would sit by the potty or she would sit on it fully clothed and I would read a book to her or we would play with stickers. After several times of that I started having her sit on the potty without a diaper on and we would still read, etc. I also told her that when she was ready and didn't need diapers anymore then we would have a "Big Girl Party" with cake and balloons and presents. She loved to talk about having the "Big Girl Party" and all the things she wanted. A few days later it just "clicked" with her and she was ok with using the potty. Over the next 2 weeks or so she had a couple of accidents, but since that time she's been awesome at it. Oh, and we had a princess themed "Big Girl Party" which she still talks about several months later. :)