(つらぬく) To penetrate all the way through:not just violently. The river runs through the town. Also, to see a project all the way through to the end.
(つく) To poke or jab, but not necessarily with a sharp object. Could be your finger.
(さす) To stab.   $$$
(さす) To insert for decorative purposes:put a flower in your buttonhole. Wear a flower in your hair. Other than that, it’s not used by itself, only in compound words.
(そうにゅう) Insert. This is the one you use about dicks. But it’s not always a dirty word. “Insert a CD into the disk drive” uses 挿入 also.