Step 1: Find a Strider with a saddle.

Step 2: Go to "sneaking mode" by using shift button.

Step 3: Try to right-click on Strider as to remove the saddle.

This will start an attempt to mount the Strider, but, because shift button is pressed, you will dismounted (and you will fall in lava in the worst case).

In some cases if you try to mount the strider again this will block you from interact with the world, as you actually mounted the Strider, but buggy.
You will fall in lava but you will not die.