The Dako peroxidase block does contain hydrogen peroxidase, in fact, 0.03%,
along with some sodium azide, approx. 0.01M, and is in buffer not methanol.

Methanol is not advisable for CD markers on frozens, not only did it chew my
sections off, but murine markers may not work, PBS with H2O2 is better. 
Biogenex and Pharmingen have both indicated this.

Gayle Callis