"Stosh" (the Polish diminutive nickname for "Stanislau") realized that he wanted a show-business career while he was in grammar school, and after he graduated from Brooklyn's P.S.

Among his friends, he was known offscreen as "Stosh", so he adopted the nickname "Stash" in the ensemble-cast film series the East Side Kids.

He retained the character name of "Stash" in other films: Right to the Heart, Military Academy with That Tenth Avenue Gang, and Boots Malone.

When he returned in 1947, he began appearing in more adult roles in lower-budgeted films, including Johnny Holiday (cast against type as a psychopath) and Destination Murder (as a hired killer).

When the series's then-producer Ben Schwalb needed a replacement for Gorcey, he asked Clements to step in as The Bowery Boys' new ringleader, Stanislaus "Duke" Coveleskie (although Huntz Hall received top billing).

Clements comfortably settled into the role of Huntz Hall's sidekick, and co-starred in the final seven Bowery Boys comedies, beginning with Fighting Trouble.

In 1960, Clements appeared as Clyde Simpson in the TV western Tales of Wells Fargo, starring Dale Robertson, in the episode "Doc Dawson".