Are stone walls effective against a trush?

A tower costs as much as 25 stone walls. Can stone walls be used to protect your base against a tower rush?

1v1 Land Madness | Koreans vs Berbers | vs TaToH

Also, if you see a tower coming up but are too late for a counter tower to finish first, how effective would it be to wall in the enemy builders so they can't escape to an earlier tower or even wall them inside a tower if they garrison in it?