[en] Low-temperature nuclear orientation experiments on radioactive ⁵⁶Mn ions implanted into insulating, antiferromagnetic crystals of MnCl₂·4H₂O and CoCl₂·6H₂O are reported. In MnCl₂·4H₂O, comparison of the γ-ray anisotropy of the ⁵⁶Mn nuclei with that of ⁵⁴Mn, doped into the sample during growth, showed that both the ⁵⁶Mn and ⁵⁴Mn spins felt a very similar hyperfine field. The site occupancy factor in a simple, two-site model was deduced to be 0.96_-0.07^+0.04. In CoCl₂·6H₂O, the average hyperfine field for the implanted ⁵⁶Mn was significantly less than that for ⁵⁴Mn and corresponded to f=0.53±0.10