If you want to rid yourself of the for loop every time you go through the while you could build up a combined regular expression match before entering the loop....something like:

use strict;
use warnings;

my @final_array=qw/test1 test2 fred/;
my $regexp = "(" . join("|", @final_array) . ")";

while(<DATA>){
  s/$regexp/pagingRAC/g; 
  print $_;
}

__DATA__
this is a test
this line contains test1 and test2
fred bassett is a dog but I can't spell his name.
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This makes it a little cleaner for the eye.