Flock vs herd

And "herd" vs. "heard".

Lol, likely "all purpose"

"Principal" vs. "principle"

In this case, it's likely "principle",
and "experimented" instead of "experimental".

Maybe they meant all-purpose?

Hand-written reminder if homophones

Just a Little Reminder to Yourself

"Rung" a bell vs "step" on a ladder

Past tense verb "rung" a bell vs the verb "step" on a ladder "rung".

Example: No vs know

An example from The Princess Bride:
I have spent the night pondering and I know no more than when I started.

Denier Vs one who denies

Denier

Rued vs rude, ruse vs rues

Werewolf vs where?

Ascent vs assent

Been vs bin

Reb-el and RE-bel

"Baited" Versus "Bated"

https://www.quickanddirtytips.com/education/grammar/baited-versus-bated

You're example

When Your'e On a Diet http://cheezburger.com/9154056448/when-youre-on-a-diet

Bated Vs baited breath

https://www.quickanddirtytips.com/education/grammar/baited-versus-bated?page=all
Fortunately, nothing to do with worms.

Tear, tears, tare

Fore vs four

Grown vs groan

close - near, close - verb, clothes - noun