As a Teacher or Parent it is important to remember that students do need to review concepts on a regular basis. It is also important to note that some students are going to view finding too many words of a similar nature as unnecessary, boring or even as a punishment. Find the right balance using the variety of worksheets available to keep students interested and if a student has mastered a task, keep it brief (don't use it as a time filler).
Young students generally find a standard Crossword a challenge but this can become
more interesting if the teacher uses the other puzzles as a variation.
Consider making an overhead transparency and have the whole class participate
in solving the puzzle in a cooperative group effort.