Dear unfortunately no answer for this

I have no experience with bone tissue but I have done extensive work with post-embedded epoxy sections of brain cut at semi-thin (1.0 µm), de-plasticized and immuno-stained on the slide with peroxidase labeling and counterstaining.  I used either ethanolic or methanolic sodium hydroxide (careful to keep solutions anhydrous).  Deplasticizing took 1hr to overnight depending on the hardness of the epoxy.  Times must be determined empirically.  Rehydration is followed by buffer rinses and then immunoreagents, blocking serum, primary, avidin-biotin/peroxidase labeling - all done on the slide.   Larue, D.T., and Winer, J.A.  Postembedding immunocytochemistry of large sections of brain tissue: an improved flat-embedding technique.  Journal of Neuroscience Methods, 1996, 68:125-132. 

Hello Dr.David, thank you for answering! I totally agree with you, we need to consider hardness of the epoxy and standardize protocol accordingly. I will go through the paper you suggested here. Meanwhile I made few changes in the protocol such as replacing acetone with xylene and avoiding agitation during deplastinization. Seems like it works.