These work by making use of double meanings and shifts in shades of meaning. The one I remember from that old magazine article connects safe with unsafe in six words:
safe - undamaged - untarnished - polished - slippery - unsafe
An object that's been through a calamity is safe if it's undamaged.
A reputation is undamaged if it's untarnished.
A metal surface is untarnished if it's polished.
If a stone is polished, it's slippery.
If a floor is slippery, it's unsafe.
All the rest in this post are ones I've come up with.
naked - unadorned - unembellished - honest - decent - clothed
If a person is naked, he's unadorned.
If an object is unadorned, it's unembellished.
If a story is unembellished, it's honest.
If a person is honest, he's decent.
A person's body is decent if it's clothed.
young - inexperienced - ineffectual - weak - feeble - senile - old
If a person is young, he's inexperienced.
If an employee is inexperienced, he may be ineffectual.
If a method is ineffectual, it's weak.
If an attempt is weak, it's feeble.
A person is feeble if he's senile; he's also old.
Young/old can also be linked by a much shorter chain:
young - green - rotten - old
If wood is young, it's green.
If meat is green, it's rotten, and indeed old.
More, in descending order of length:
true - straight - even - horizontal - lying - false
intelligent - witty - funny - silly - stupid - unintelligent
awake - alert - thinking - hoping - dreaming - asleep
large - inflated - stretched - thin - meager - small
tidy - fussy - whiny - selfish - inconsiderate - messy
serious - insistent - loud - bright-colored - whimsical - playful
create - make - do - execute - kill - destroy
fast - tight - restricted - burdened - retarded - slow
happy - overjoyed - emotional - distraught - unhappy
happy - complacent - jaded - bored - unhappy
perfect - finished - ruined - broken - imperfect
hard - dense - stupid - simple - easy
strong - smelly - rotten - old - weak
good - delicious - tempting - sinful - evil
inert - useless - broken - unstable - explosive
alive - breathing - outgassing - putrefying - dead
hot - angry - hateful - heartless - cold
left - remaining - prevailing - accepted - right
visible - obvious - clear - transparent - invisible
normal - typical - characteristic - peculiar - weird
same - repeated - redone - different
It's possible to form some chains in just three words by making use of a bridging word that has two self-contradictory meanings:
clean - dusted - dirty
attached - clipped - detached
And finally, here's one that uses several associations of varying degrees of political incorrectness to work:
black - urban - sophisticated - civilized - white