Just wondering if anyone knows of other similar wordplay jokes like this, with substituing letters for humours results

If so, feel free to add them
What's the difference between a mountain goat and a goldfish?
The goldfish mucks about the fountain, the goat...
What's the difference between the pope and a woman in a bath?
One has got hope in the soul, the other has soap in the...
Difference between a magician's wand and a policeman's baton?
Once is for cunning stunts, the other is for stunning...
What is the difference between a circus and a group of blondes?
At the circus you'll find a cunning array of stunts, the blondes you'll find a...
What's the difference between a maid and a prostitute?
The maid is fair and buxom, the prostitue...