Never but came close a couple of times. One time I was tied up and forced to drink two quarts of warm, flat soda and then left tied while the soda went through me with the specific purpose of my wetting myself in mind, but fortunately I was rescued just in time by someone else. A different time was self-bondage done too well when I was in my early 30s; I had to rip out the bed railing to free myself (I was strong and desperate, and the bed railing not all THAT sturdy).
Now, being wet on by someone else while tied up... that's a different matter.

But you didn't ask about THAT so I won't elaborate.
Dare to be different... and make a difference.
To boldly go where no one in their right mind has gone before...