Extreme Pain slave here

Was that a fire ants hole? If so thats pretty impressive.

My task for you, and hopefully you are able to set this up and it works...

Get a weight and tie it to your balls. This weight should be quite heavy and have a rope several feet long so that you need to walk backwards dragging it with your balls. Ensure the weight is enough that this hurts but it wont cause any serious harm. Also be the weight sure it cannot tip over and spill out or something.

With this ready tie a rope to a wall about 10 feet behind you and tie the other end to some handcuffs. leave the key at the wall. You will start at the ropes end from the wall with the weight at the end of its rope even further away from the wall.

If setup correctly once you cuff your hands behind your back you shouldnt be able to eaisly move. The rope on your cuffs prevents you from getting to the weight atleast until you have moved it some and you need to draw that weight all the way to the wall to get your cuffs key.

Be sure the weight wont get caught on anything.
If you like this task you can eaisly make it as hard as you like by increasing the length of the rope and/or weight or adding a time limit with a punishment if you take to long.