One of the most effective online dereverberation algorithms is the weighted prediction error (WPE) method and its improved version, switching WPE (SwWPE). This paper proposes a practical online dereverberation approach to improve SwWPE by introducing a datareuse technique, DR-SwWPE; we then show analytically that DR-SwWPE is equivalent to a SwWPE followed by a post-filter to suppress the residual reverberation. Secondly, we compare this suppression technique and two explicit post-filtering schemes to SwWPE using both simulated data and real-world recordings. Experimental results show that DR-SwWPE out-performs SwWPE with little additional computational cost.