Is it ok to gargle with hand sanitizer?

I took Zach in a public restroom and forgot his little travel potty seat at home so I had to hold him on the potty and he holds on for dear life too. He was touching the bare toilet seat and I was grossed out but I kept thinking to myself...it's ok, I will wash his hands as soon as he is done. He finished going potty and stands up and I help him pull up his pants. He reaches down to help me and his thumb...that was on the bare toilet seat and hasn't been washed yet went in yes, IN my mouth! I was so grossed out but I laughed anyway. Kids!