Lions boss Willie Donachie drafted in the Watford striker on loan this week because all his forwards had failed to get off the mark in his side's previous six games.
Hoskins was withdrawn after the hour mark after failing to provide the killer touch Millwall were crying out for after dominating much of the game, but Crewe also lacked a punch up front.
The closest they got to scoring was when right-back Danny Woodards saw his crashing drive brilliantly saved by former Scotland international Rab Douglas in a game of few clear-cut chances.
The visitors were on top in the first half with Arsenal loan ace Jay Simpson the pick of the bunch.
But despite the Londoners' domination, they only really went close to breaking the deadlock once when former Crewe captain Dave Brammer set up Gary Alexander at the far post but the striker shot straight at home keeper Ben Williams.
Ryan Lowe spurned a presentable opportunity for the hosts three minutes before the break when he was played in by Ben Rix but curled his effort a yard wide of the post.
The first half was tame entertainment and the second half was really dire stuff.
Donachie turned a few heads when he took off Simpson for fitness reasons, although the youngster seemed to be the best bet to make a breakthrough.
Before his departure, Simpson arced a left footer just past the upright.
In the dying minutes, Crewe loan striker Lee Barnard blazed over from a difficult angle before Woodards almost stole the glory.