The composition of our bead blocking solution is:
5 mg/mL Hammarsten-grade casein in 25 mM Tris, 150 mM NaCl, pH 7.4 containing 600 ppm Kathon anti-microbial agent and 0.05% anti-foam A.
You CAN use BSA in place of casein, but sometimes BSA may contain a small amount of biotin, which will bind to the SA. If BSA is not a problem with any of your downstream applications, then yes, it should be fine to use this as a blocking agent