to teach thoroughly; to instill (into); to instil; to inculcate; to drum (into); to drill (into); to hammer (into)
礼儀をきちんと教え込んだ。
I drilled proper etiquette into them.
子供に食事のマナーを教え込んでいる。
I'm drilling table manners into the children.
良い習慣は幼い頃から教え込むべきだ。
Good habits should be drilled in from an early age.